diff --git a/.gitignore b/.gitignore
index 46060552..af16e87b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,9 +4,11 @@
 /config/secrets.yml
 /config/sendmail.yml
 /config/smtp.yml
-/config/docker.yml.erb
+/config/docker.yml*.erb
 /config/*.production.yml
 /config/*.staging.yml
+/config/*.staging-epic.yml
+/config/deploy/staging-epic.rb
 /coverage
 /log
 /public/assets
@@ -14,6 +16,7 @@
 /rubocop.html
 /tmp
 /vagrant/
+/.capistrano
 /.vagrant
 *.sublime-*
 /.idea
diff --git a/Gemfile b/Gemfile
index afd0aeff..8595fdf9 100644
--- a/Gemfile
+++ b/Gemfile
@@ -8,7 +8,7 @@ gem 'coffee-rails', '~> 4.0.0'
 gem 'concurrent-ruby', '~> 1.0.1'
 gem 'concurrent-ruby-ext', '~> 1.0.1', platform: :ruby
 gem 'docker-api','~> 1.25.0',  require: 'docker'
-gem 'factory_girl_rails', '~> 4.0'
+gem 'factory_bot_rails', '~> 4.8.2'
 gem 'forgery'
 gem 'highline'
 gem 'jbuilder', '~> 2.0'
diff --git a/Gemfile.lock b/Gemfile.lock
index 67860f20..901aa706 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -125,10 +125,10 @@ GEM
     eventmachine (1.0.9.1-java)
     excon (0.54.0)
     execjs (2.6.0)
-    factory_girl (4.5.0)
+    factory_bot (4.8.2)
       activesupport (>= 3.0.0)
-    factory_girl_rails (4.6.0)
-      factory_girl (~> 4.5.0)
+    factory_bot_rails (4.8.2)
+      factory_bot (~> 4.8.2)
       railties (>= 3.0.0)
     faraday (0.9.2)
       multipart-post (>= 1.2, < 3)
@@ -401,7 +401,7 @@ DEPENDENCIES
   d3-rails
   database_cleaner
   docker-api (~> 1.25.0)
-  factory_girl_rails (~> 4.0)
+  factory_bot_rails (~> 4.8.2)
   faye-websocket
   forgery
   highline
diff --git a/app/assets/javascripts/editor/editor.js.erb b/app/assets/javascripts/editor/editor.js.erb
index 2d145e34..f6ff6887 100644
--- a/app/assets/javascripts/editor/editor.js.erb
+++ b/app/assets/javascripts/editor/editor.js.erb
@@ -580,7 +580,7 @@ configureEditors: function () {
      * */
     initializeInterventionTimer: function() {
 
-        if ($('#editor').data('rfc-interventions') == true || $('#editor').data('break-interventions') == true) { // split in break or rfc intervention
+        if ($('#editor').data('rfc-interventions') || $('#editor').data('break-interventions')) { // split in break or rfc intervention
             window.onblur = function() { window.blurred = true; };
             window.onfocus = function() { window.blurred = false; };
 
diff --git a/app/assets/stylesheets/exercises.css.scss b/app/assets/stylesheets/exercises.css.scss
index e46d59af..2ef110d7 100644
--- a/app/assets/stylesheets/exercises.css.scss
+++ b/app/assets/stylesheets/exercises.css.scss
@@ -95,14 +95,43 @@ a.file-heading {
   left: 0;
 }
 
-.feedback {
-  .text {
+.feedback-page {
+  .header {
+    font-weight: bold;
     margin-bottom: 10px;
   }
-  .difficulty {
-    font-weight: bold;
+
+  .value {
+    border: 1px solid grey;
+    padding: 10px;
+    margin-bottom: 10px;
   }
-  .worktime {
+
+  .no-feedback {
     font-weight: bold;
+    margin-top: 50px;
+  }
+
+  .feedback-header {
+    display: flex;
+
+    .username {
+      flex-grow: 1;
+      font-weight: bold;
+    }
+
+    .date {}
+  }
+
+  .feedback {
+    .text {
+      margin-bottom: 10px;
+    }
+    .difficulty {
+      font-weight: bold;
+    }
+    .worktime {
+      font-weight: bold;
+    }
   }
 }
diff --git a/app/controllers/exercises_controller.rb b/app/controllers/exercises_controller.rb
index 969e5e4f..fa48363e 100644
--- a/app/controllers/exercises_controller.rb
+++ b/app/controllers/exercises_controller.rb
@@ -24,6 +24,9 @@ class ExercisesController < ApplicationController
     3
   end
 
+  def max_intervention_count_per_exercise
+    1
+  end
 
   def java_course_token
     "702cbd2a-c84c-4b37-923a-692d7d1532d0"
@@ -148,8 +151,7 @@ class ExercisesController < ApplicationController
   private :user_by_code_harbor_token
 
   def exercise_params
-    params[:exercise][:expected_worktime_seconds] = params[:exercise][:expected_worktime_minutes].to_i * 60
-    params[:exercise].permit(:description, :execution_environment_id, :file_id, :instructions, :public, :hide_file_tree, :allow_file_creation, :allow_auto_completion, :title, :expected_difficulty, :expected_worktime_seconds, files_attributes: file_attributes, :tag_ids => []).merge(user_id: current_user.id, user_type: current_user.class.name)
+    params[:exercise].permit(:description, :execution_environment_id, :file_id, :instructions, :public, :hide_file_tree, :allow_file_creation, :allow_auto_completion, :title, :expected_difficulty, files_attributes: file_attributes, :tag_ids => []).merge(user_id: current_user.id, user_type: current_user.class.name)
   end
   private :exercise_params
 
@@ -171,17 +173,19 @@ class ExercisesController < ApplicationController
   def implement
     redirect_to(@exercise, alert: t('exercises.implement.no_files')) unless @exercise.files.visible.exists?
     user_solved_exercise = @exercise.has_user_solved(current_user)
-    user_got_enough_interventions = UserExerciseIntervention.where(user: current_user).where("created_at >= ?", Time.zone.now.beginning_of_day).count >= max_intervention_count_per_day
-    is_java_course = @course_token && @course_token.eql?(java_course_token)
+    count_interventions_today = UserExerciseIntervention.where(user: current_user).where("created_at >= ?", Time.zone.now.beginning_of_day).count
+    user_got_intervention_in_exercise = UserExerciseIntervention.where(user: current_user, exercise: @exercise).size >= max_intervention_count_per_exercise
+    user_got_enough_interventions = count_interventions_today >= max_intervention_count_per_day or user_got_intervention_in_exercise
+    is_java_course = @course_token and @course_token.eql?(java_course_token)
 
     user_intervention_group = UserGroupSeparator.getInterventionGroup(current_user)
 
     case user_intervention_group
       when :no_intervention
       when :break_intervention
-        @show_break_interventions = (user_solved_exercise || !is_java_course || user_got_enough_interventions) ? "false" : "true"
+        @show_break_interventions = (not user_solved_exercise and is_java_course and not user_got_enough_interventions) ? "true" : "false"
       when :rfc_intervention
-        @show_rfc_interventions = (user_solved_exercise || !is_java_course || user_got_enough_interventions) ? "false" : "true"
+        @show_rfc_interventions = (not user_solved_exercise and is_java_course and not user_got_enough_interventions) ? "true" : "false"
     end
 
     @search = Search.new
@@ -387,10 +391,13 @@ class ExercisesController < ApplicationController
       # otherwise an internal user could be shown a false rfc here, since current_user.id is polymorphic, but only makes sense for external users when used with rfcs.)
       # redirect 10 percent pseudorandomly to the feedback page
       if current_user.respond_to? :external_id
-        if ((current_user.id + @submission.exercise.created_at.to_i) % 10 == 1)
+        if @submission.redirect_to_feedback?
           redirect_to_user_feedback
           return
-        elsif rfc = RequestForComment.unsolved.where(exercise_id: @submission.exercise, user_id: current_user.id).first
+        end
+
+        rfc = @submission.own_unsolved_rfc
+        if rfc
           # set a message that informs the user that his own RFC should be closed.
           flash[:notice] = I18n.t('exercises.submit.full_score_redirect_to_own_rfc')
           flash.keep(:notice)
@@ -400,24 +407,30 @@ class ExercisesController < ApplicationController
             format.json { render(json: {redirect: url_for(rfc)}) }
           end
           return
+        end
 
         # else: show open rfc for same exercise if available
-        elsif rfc = RequestForComment.unsolved.where(exercise_id: @submission.exercise).where.not(question: nil).order("RANDOM()").find { | rfc_element |(rfc_element.comments_count < 5) }
+        rfc = @submission.unsolved_rfc
+        unless rfc.nil?
           # set a message that informs the user that his score was perfect and help in RFC is greatly appreciated.
           flash[:notice] = I18n.t('exercises.submit.full_score_redirect_to_rfc')
           flash.keep(:notice)
 
           respond_to do |format|
-            format.html { redirect_to(rfc) }
-            format.json { render(json: {redirect: url_for(rfc)}) }
+            format.html {redirect_to(rfc)}
+            format.json {render(json: {redirect: url_for(rfc)})}
           end
           return
         end
       end
     else
       # redirect to feedback page if score is less than 100 percent
-       redirect_to_user_feedback
-      return
+       if @exercise.needs_more_feedback?
+         redirect_to_user_feedback
+       else
+         redirect_to_lti_return_path
+       end
+       return
     end
     redirect_to_lti_return_path
   end
diff --git a/app/controllers/submissions_controller.rb b/app/controllers/submissions_controller.rb
index 8e7a8e39..73db8c25 100644
--- a/app/controllers/submissions_controller.rb
+++ b/app/controllers/submissions_controller.rb
@@ -390,7 +390,7 @@ class SubmissionsController < ApplicationController
     content += "#{request.base_url}/evaluate\n"
     @submission.files.each do |file|
       file_path = file.path.to_s == '' ? file.name_with_extension : File.join(file.path, file.name_with_extension)
-      content += "#{file_path}=#{file.id.to_s}\n"
+      content += "#{file_path}=#{file.file_id.to_s}\n"
     end
     File.open(path, "w+") do |f|
       f.write(content)
diff --git a/app/controllers/user_exercise_feedbacks_controller.rb b/app/controllers/user_exercise_feedbacks_controller.rb
index 0d1e1925..8abffd66 100644
--- a/app/controllers/user_exercise_feedbacks_controller.rb
+++ b/app/controllers/user_exercise_feedbacks_controller.rb
@@ -2,6 +2,7 @@ class UserExerciseFeedbacksController < ApplicationController
   include CommonBehavior
 
   before_action :set_user_exercise_feedback, only: [:edit, :update]
+  before_action :set_user_exercise_feedback_by_id, only: [:show, :destroy]
 
   def comment_presets
     [[0,t('user_exercise_feedback.difficulty_easy')],
@@ -19,10 +20,15 @@ class UserExerciseFeedbacksController < ApplicationController
      [4,t('user_exercise_feedback.estimated_time_more_30')]]
   end
 
-  def authorize!
-    authorize(@uef)
+  def index
+    @search = UserExerciseFeedback.all.search params[:q]
+    @uefs = @search.result.includes(:execution_environment).order(:id).paginate(page: params[:page])
+    authorize!
+  end
+
+  def show
+    authorize!
   end
-  private :authorize!
 
   def create
     @exercise = Exercise.find(uef_params[:exercise_id])
@@ -49,7 +55,8 @@ class UserExerciseFeedbacksController < ApplicationController
   end
 
   def destroy
-    destroy_and_respond(object: @tag)
+    authorize!
+    destroy_and_respond(object: @uef)
   end
 
   def edit
@@ -58,11 +65,6 @@ class UserExerciseFeedbacksController < ApplicationController
     authorize!
   end
 
-  def uef_params
-    params[:user_exercise_feedback].permit(:feedback_text, :difficulty, :exercise_id, :user_estimated_worktime).merge(user_id: current_user.id, user_type: current_user.class.name)
-  end
-  private :uef_params
-
   def new
     @texts = comment_presets.to_a
     @times = time_presets.to_a
@@ -89,6 +91,12 @@ class UserExerciseFeedbacksController < ApplicationController
     end
   end
 
+  private
+
+  def authorize!
+    authorize(@uef || @uefs)
+  end
+
   def to_s
     name
   end
@@ -98,6 +106,14 @@ class UserExerciseFeedbacksController < ApplicationController
     @uef = UserExerciseFeedback.find_by(exercise_id: params[:user_exercise_feedback][:exercise_id], user: current_user)
   end
 
+  def set_user_exercise_feedback_by_id
+    @uef = UserExerciseFeedback.find(params[:id])
+  end
+
+  def uef_params
+    params[:user_exercise_feedback].permit(:feedback_text, :difficulty, :exercise_id, :user_estimated_worktime).merge(user_id: current_user.id, user_type: current_user.class.name)
+  end
+
   def validate_inputs(uef_params)
     begin
       if uef_params[:difficulty].to_i < 0 || uef_params[:difficulty].to_i >= comment_presets.size
@@ -112,4 +128,4 @@ class UserExerciseFeedbacksController < ApplicationController
     end
   end
 
-end
\ No newline at end of file
+end
diff --git a/app/models/exercise.rb b/app/models/exercise.rb
index b7487399..f03d6641 100644
--- a/app/models/exercise.rb
+++ b/app/models/exercise.rb
@@ -37,6 +37,8 @@ class Exercise < ActiveRecord::Base
 
   @working_time_statistics = nil
 
+  MAX_EXERCISE_FEEDBACKS = 20
+
 
   def average_percentage
     if average_score and maximum_score != 0.0 and submissions.exists?(cause: 'submit')
@@ -362,4 +364,8 @@ class Exercise < ActiveRecord::Base
   end
   private :valid_main_file?
 
+  def needs_more_feedback?
+    user_exercise_feedbacks.size <= MAX_EXERCISE_FEEDBACKS
+  end
+
 end
diff --git a/app/models/submission.rb b/app/models/submission.rb
index 69a48307..d75d6019 100644
--- a/app/models/submission.rb
+++ b/app/models/submission.rb
@@ -18,6 +18,8 @@ class Submission < ActiveRecord::Base
   validates :cause, inclusion: {in: CAUSES}
   validates :exercise_id, presence: true
 
+  MAX_COMMENTS_ON_RECOMMENDED_RFC = 5
+
   def build_files_hash(files, attribute)
     files.map(&attribute.to_proc).zip(files).to_h
   end
@@ -53,4 +55,16 @@ class Submission < ActiveRecord::Base
   def to_s
     Submission.model_name.human
   end
+
+  def redirect_to_feedback?
+    ((user_id + exercise.created_at.to_i) % 10 == 1) && exercise.needs_more_feedback?
+  end
+
+  def own_unsolved_rfc
+    RequestForComment.unsolved.where(exercise_id: exercise, user_id: user_id).first
+  end
+
+  def unsolved_rfc
+    RequestForComment.unsolved.where(exercise_id: exercise).where.not(question: nil).order("RANDOM()").find { | rfc_element |(rfc_element.comments_count < MAX_COMMENTS_ON_RECOMMENDED_RFC) }
+  end
 end
diff --git a/app/models/user_exercise_feedback.rb b/app/models/user_exercise_feedback.rb
index 78d84972..5694573b 100644
--- a/app/models/user_exercise_feedback.rb
+++ b/app/models/user_exercise_feedback.rb
@@ -2,10 +2,11 @@ class UserExerciseFeedback < ActiveRecord::Base
   include Creation
 
   belongs_to :exercise
+  has_one :execution_environment, through: :exercise
 
   validates :user_id, uniqueness: { scope: [:exercise_id, :user_type] }
 
   def to_s
     "User Exercise Feedback"
   end
-end
\ No newline at end of file
+end
diff --git a/app/policies/user_exercise_feedback_policy.rb b/app/policies/user_exercise_feedback_policy.rb
index 20a89a6e..a570a28c 100644
--- a/app/policies/user_exercise_feedback_policy.rb
+++ b/app/policies/user_exercise_feedback_policy.rb
@@ -1,8 +1,4 @@
-class UserExerciseFeedbackPolicy < ApplicationPolicy
-  def author?
-    @user == @record.author
-  end
-  private :author?
+class UserExerciseFeedbackPolicy < AdminOrAuthorPolicy
 
   def create?
     everyone
@@ -12,8 +8,4 @@ class UserExerciseFeedbackPolicy < ApplicationPolicy
     everyone
   end
 
-  [:show? ,:destroy?, :edit?, :update?].each do |action|
-    define_method(action) { admin? || author?}
-  end
-
 end
diff --git a/app/views/application/_navigation.html.slim b/app/views/application/_navigation.html.slim
index 668ccab4..a2604c7a 100644
--- a/app/views/application/_navigation.html.slim
+++ b/app/views/application/_navigation.html.slim
@@ -8,7 +8,7 @@
         - if current_user.admin?
           li = link_to(t('breadcrumbs.dashboard.show'), admin_dashboard_path)
           li.divider
-        - models = [ExecutionEnvironment, Exercise, ExerciseCollection, ProxyExercise, Tag, Consumer, CodeHarborLink,
+        - models = [ExecutionEnvironment, Exercise, ExerciseCollection, ProxyExercise, Tag, Consumer, CodeHarborLink, UserExerciseFeedback,
                 ErrorTemplate, ErrorTemplateAttribute, ExternalUser, FileType, FileTemplate, InternalUser].sort_by {|model| model.model_name.human(count: 2) }
         - models.each do |model|
           - if policy(model).index?
diff --git a/app/views/exercises/_form.html.slim b/app/views/exercises/_form.html.slim
index bb4aa851..646c359a 100644
--- a/app/views/exercises/_form.html.slim
+++ b/app/views/exercises/_form.html.slim
@@ -35,9 +35,6 @@
   .form-group
     = f.label(t('activerecord.attributes.exercise.difficulty'))
     = f.number_field :expected_difficulty, in: 1..10, step: 1
-  .form-group
-    = f.label(t('activerecord.attributes.exercise.worktime'))
-    = f.number_field "expected_worktime_minutes", value: @exercise.expected_worktime_seconds / 60, in: 1..1000, step: 1
 
   h2 = t('exercises.form.tags')
   ul.list-unstyled.panel-group
diff --git a/app/views/exercises/external_users/statistics.html.slim b/app/views/exercises/external_users/statistics.html.slim
index 8b5c3b30..06132754 100644
--- a/app/views/exercises/external_users/statistics.html.slim
+++ b/app/views/exercises/external_users/statistics.html.slim
@@ -54,8 +54,6 @@ h1 = "#{@exercise} (external user #{@external_user})"
                   -submission_or_intervention.testruns.each do |run|
                     - if run.passed
                       .unit-test-result.positive-result  title=run.output
-                    - elsif run.failed
-                      .unit-test-result.negative-result title=run.output
                     - else
                       .unit-test-result.unknown-result title=run.output
                 td = Time.at(deltas[1..index].inject(:+)).utc.strftime("%H:%M:%S") if index > 0
diff --git a/app/views/exercises/feedback.html.slim b/app/views/exercises/feedback.html.slim
index 07b88167..3cdbc30f 100644
--- a/app/views/exercises/feedback.html.slim
+++ b/app/views/exercises/feedback.html.slim
@@ -1,15 +1,24 @@
-h1 = @exercise
+h1 = link_to(@exercise, exercise_path(@exercise))
 
-ul.list-unstyled.panel-group#files
-  - @feedbacks.each do |feedback|
-    li.panel.panel-default
-      .panel-heading role="tab" id="heading"
-        div.clearfix
-          span = feedback.user.name
-      .panel-collapse role="tabpanel"
-        .panel-body.feedback
-          .text = feedback.feedback_text
-          .difficulty = "#{t('user_exercise_feedback.difficulty')} #{feedback.difficulty}" if feedback.difficulty
-          .worktime = "#{t('user_exercise_feedback.working_time')} #{feedback.user_estimated_worktime}" if feedback.user_estimated_worktime
+.feedback-page
+  .header = t('activerecord.attributes.exercise.description')
+  .value = render_markdown(@exercise.description)
 
-= render('shared/pagination', collection: @feedbacks)
+  .header = t('activerecord.models.user_exercise_feedback.other')
+  - if @feedbacks.nil? or @feedbacks.size == 0
+    .no-feedback = t('user_exercise_feedback.no_feedback')
+
+  ul.list-unstyled.panel-group
+    - @feedbacks.each do |feedback|
+      li.panel.panel-default
+        .panel-heading role="tab" id="heading"
+          div.clearfix.feedback-header
+            span.username = link_to(feedback.user.name, statistics_external_user_exercise_path(id: @exercise.id, external_user_id: feedback.user.id))
+            span.date = feedback.created_at
+        .panel-collapse role="tabpanel"
+          .panel-body.feedback
+            .text = feedback.feedback_text
+            .difficulty = "#{t('user_exercise_feedback.difficulty')} #{feedback.difficulty}" if feedback.difficulty
+            .worktime = "#{t('user_exercise_feedback.working_time')} #{feedback.user_estimated_worktime}" if feedback.user_estimated_worktime
+
+  = render('shared/pagination', collection: @feedbacks)
diff --git a/app/views/exercises/index.html.slim b/app/views/exercises/index.html.slim
index 18c2cd98..47198fbb 100644
--- a/app/views/exercises/index.html.slim
+++ b/app/views/exercises/index.html.slim
@@ -18,7 +18,6 @@ h1 = Exercise.model_name.human(count: 2)
         th = t('activerecord.attributes.exercise.maximum_score')
         th = t('activerecord.attributes.exercise.tags')
         th = t('activerecord.attributes.exercise.difficulty')
-        th = t('activerecord.attributes.exercise.worktime')
         th
           = t('activerecord.attributes.exercise.public')
           - if policy(Exercise).batch_update?
@@ -34,7 +33,6 @@ h1 = Exercise.model_name.human(count: 2)
           td = exercise.maximum_score
           td = exercise.exercise_tags.count
           td = exercise.expected_difficulty
-          td = (exercise.expected_worktime_seconds / 60).ceil
           td.public data-value=exercise.public? = symbol_for(exercise.public?)
           td = link_to(t('shared.edit'), edit_exercise_path(exercise)) if policy(exercise).edit?
           td = link_to(t('.implement'), implement_exercise_path(exercise)) if policy(exercise).implement?
diff --git a/app/views/exercises/show.html.slim b/app/views/exercises/show.html.slim
index 1efbd612..e3dfc7d5 100644
--- a/app/views/exercises/show.html.slim
+++ b/app/views/exercises/show.html.slim
@@ -20,7 +20,6 @@ h1
 = row(label: 'exercise.embedding_parameters') do
   = content_tag(:input, nil, class: 'form-control', readonly: true, value: embedding_parameters(@exercise))
 = row(label: 'exercise.difficulty', value: @exercise.expected_difficulty)
-= row(label: 'exercise.worktime', value: "#{@exercise.expected_worktime_seconds/60} min")
 = row(label: 'exercise.tags', value: @exercise.exercise_tags.map{|et| "#{et.tag.name} (#{et.factor})"}.sort.join(", "))
 
 h2 = t('activerecord.attributes.exercise.files')
diff --git a/app/views/user_exercise_feedbacks/index.html.slim b/app/views/user_exercise_feedbacks/index.html.slim
new file mode 100644
index 00000000..52249229
--- /dev/null
+++ b/app/views/user_exercise_feedbacks/index.html.slim
@@ -0,0 +1,27 @@
+h1 = UserExerciseFeedback.model_name.human(count: 2)
+
+= render(layout: 'shared/form_filters') do |f|
+  .form-group
+    = f.label(:execution_environment_id_eq, t('activerecord.attributes.exercise.execution_environment'), class: 'sr-only')
+    = f.collection_select(:execution_environment_id_eq, ExecutionEnvironment.with_exercises, :id, :name, class: 'form-control', prompt: t('activerecord.attributes.exercise.execution_environment'))
+  .form-group
+    = f.label(:exercise_title_cont, t('activerecord.attributes.request_for_comments.exercise'), class: 'sr-only')
+    = f.search_field(:exercise_title_cont, class: 'form-control', placeholder: t('activerecord.attributes.request_for_comments.exercise'))
+
+.table-responsive
+  table.table
+    thead
+      tr
+        th colspan=2 = t('activerecord.attributes.user_exercise_feedback.user')
+        th = t('activerecord.attributes.user_exercise_feedback.exercise')
+        th colspan=2 = t('shared.actions')
+    tbody
+      - @uefs.each do |uef|
+        tr
+          td = uef.user.id
+          td = uef.user.name
+          td = link_to(uef.exercise.title, uef.exercise)
+          td = link_to(t('shared.show'), uef)
+          td = link_to(t('shared.destroy'), uef, data: {confirm: t('shared.confirm_destroy')}, method: :delete)
+
+= render('shared/pagination', collection: @uefs)
diff --git a/app/views/user_exercise_feedbacks/show.html.slim b/app/views/user_exercise_feedbacks/show.html.slim
new file mode 100644
index 00000000..2c53e47f
--- /dev/null
+++ b/app/views/user_exercise_feedbacks/show.html.slim
@@ -0,0 +1,7 @@
+h2 = @uef
+
+= row(label: 'activerecord.attributes.user_exercise_feedback.exercise', value: link_to(@uef.exercise.title, @uef.exercise))
+= row(label: 'user_exercise_feedback.user', value: @uef.user)
+= row(label: 'activerecord.attributes.user_exercise_feedback.feedback_text', value: @uef.feedback_text)
+= row(label: 'user_exercise_feedback.difficulty', value: @uef.difficulty)
+= row(label: 'user_exercise_feedback.working_time', value: @uef.user_estimated_worktime)
diff --git a/config/locales/de.yml b/config/locales/de.yml
index 9754caac..1e7d1d00 100644
--- a/config/locales/de.yml
+++ b/config/locales/de.yml
@@ -41,7 +41,6 @@ de:
         allow_auto_completion: "Autovervollständigung aktivieren"
         allow_file_creation: "Dateierstellung erlauben"
         difficulty: Schwierigkeitsgrad
-        worktime: "vermutete Arbeitszeit in Minuten"
         token: "Aufgaben-Token"
       proxy_exercise:
         title: Title
@@ -128,6 +127,10 @@ de:
         use_anomaly_detection: "Abweichungen in der Arbeitszeit erkennen"
         updated_at: "Letzte Änderung"
         exercises: "Aufgaben"
+      user_exercise_feedback:
+        user: "Autor"
+        exercise: "Aufgabe"
+        feedback_text: "Feedback Text"
     models:
       code_harbor_link:
         one: CodeHarbor-Link
@@ -692,6 +695,7 @@ de:
     estimated_time_20_to_30: "zwischen 20 und 30 Minuten"
     estimated_time_more_30: "mehr als 30 Minuten"
     working_time: "Geschätze Bearbeitungszeit für diese Aufgabe:"
+    no_feedback: "Es wurde noch kein Feedback zu dieser Aufgabe gegeben."
   error_templates:
     hints:
       signature: "Ein regulärer Ausdruck in Ruby-Syntax und ohne führende und schließende \"/\""
diff --git a/config/locales/en.yml b/config/locales/en.yml
index 777ee9b7..d5e8cd4d 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -41,7 +41,6 @@ en:
         allow_auto_completion: "Allow auto completion"
         allow_file_creation: "Allow file creation"
         difficulty: Difficulty
-        worktime: "Expected worktime in minutes"
         token: "Exercise Token"
       proxy_exercise:
         title: Title
@@ -128,6 +127,10 @@ en:
         use_anomaly_detection: "Enable Worktime Anomaly Detection"
         updated_at: "Last Update"
         exercises: "Exercises"
+      user_exercise_feedback:
+        user: "Author"
+        exercise: "Exercise"
+        feedback_text: "Feedback Text"
     models:
       code_harbor_link:
         one: CodeHarbor Link
@@ -692,6 +695,7 @@ en:
     estimated_time_20_to_30: "between 20 and 30 minutes"
     estimated_time_more_30: "more than 30 minutes"
     working_time: "Estimated time working on this exercise:"
+    no_feedback: "There is no feedback for this exercise yet."
   error_templates:
     hints:
       signature: "A regular expression in Ruby syntax without leading and trailing \"/\""
diff --git a/db/migrate/20171002131135_remove_expected_working_time.rb b/db/migrate/20171002131135_remove_expected_working_time.rb
new file mode 100644
index 00000000..eb4bbcb4
--- /dev/null
+++ b/db/migrate/20171002131135_remove_expected_working_time.rb
@@ -0,0 +1,5 @@
+class RemoveExpectedWorkingTime < ActiveRecord::Migration
+  def change
+    remove_column :exercises, :expected_worktime_seconds
+  end
+end
diff --git a/db/migrate/20171120153705_add_timestamps_to_user_exercise_feedbacks.rb b/db/migrate/20171120153705_add_timestamps_to_user_exercise_feedbacks.rb
new file mode 100644
index 00000000..4529d527
--- /dev/null
+++ b/db/migrate/20171120153705_add_timestamps_to_user_exercise_feedbacks.rb
@@ -0,0 +1,6 @@
+class AddTimestampsToUserExerciseFeedbacks < ActiveRecord::Migration
+  def up
+    add_column :user_exercise_feedbacks, :created_at, :datetime, null: false, default: Time.now
+    add_column :user_exercise_feedbacks, :updated_at, :datetime, null: false, default: Time.now
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 474aa6f1..828e8e41 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -128,19 +128,18 @@ ActiveRecord::Schema.define(version: 20171210172208) do
   create_table "exercises", force: :cascade do |t|
     t.text     "description"
     t.integer  "execution_environment_id"
-    t.string   "title",                     limit: 255
+    t.string   "title",                    limit: 255
     t.datetime "created_at"
     t.datetime "updated_at"
     t.integer  "user_id"
     t.text     "instructions"
     t.boolean  "public"
-    t.string   "user_type",                 limit: 255
-    t.string   "token",                     limit: 255
+    t.string   "user_type",                limit: 255
+    t.string   "token",                    limit: 255
     t.boolean  "hide_file_tree"
     t.boolean  "allow_file_creation"
-    t.boolean  "allow_auto_completion",                 default: false
-    t.integer  "expected_worktime_seconds",             default: 60
-    t.integer  "expected_difficulty",                   default: 1
+    t.boolean  "allow_auto_completion",                default: false
+    t.integer  "expected_difficulty",                  default: 1
   end
 
   add_index "exercises", ["id"], name: "index_exercises_on_id", using: :btree
@@ -355,13 +354,15 @@ ActiveRecord::Schema.define(version: 20171210172208) do
   end
 
   create_table "user_exercise_feedbacks", force: :cascade do |t|
-    t.integer "exercise_id",             null: false
-    t.integer "user_id",                 null: false
-    t.string  "user_type",               null: false
-    t.integer "difficulty"
-    t.integer "working_time_seconds"
-    t.string  "feedback_text"
-    t.integer "user_estimated_worktime"
+    t.integer  "exercise_id",                                             null: false
+    t.integer  "user_id",                                                 null: false
+    t.string   "user_type",                                               null: false
+    t.integer  "difficulty"
+    t.integer  "working_time_seconds"
+    t.string   "feedback_text"
+    t.integer  "user_estimated_worktime"
+    t.datetime "created_at",              default: '2017-11-20 18:20:25', null: false
+    t.datetime "updated_at",              default: '2017-11-20 18:20:25', null: false
   end
 
   create_table "user_exercise_interventions", force: :cascade do |t|
diff --git a/db/seeds.rb b/db/seeds.rb
index 823a6358..28d543ef 100644
--- a/db/seeds.rb
+++ b/db/seeds.rb
@@ -1,5 +1,5 @@
 def find_factories_by_class(klass)
-  FactoryGirl.factories.select do |factory|
+  FactoryBot.factories.select do |factory|
     factory.instance_variable_get(:@class_name) == klass || factory.instance_variable_get(:@name) == klass.model_name.singular.to_sym
   end
 end
@@ -9,7 +9,7 @@ module ActiveRecord
     [:build, :create].each do |strategy|
       define_singleton_method("#{strategy}_factories") do |attributes = {}|
         find_factories_by_class(self).map(&:name).map do |factory_name|
-          FactoryGirl.send(strategy, factory_name, attributes)
+          FactoryBot.send(strategy, factory_name, attributes)
         end
       end
     end
diff --git a/db/seeds/development.rb b/db/seeds/development.rb
index 6fc8e050..b0c550c0 100644
--- a/db/seeds/development.rb
+++ b/db/seeds/development.rb
@@ -1,9 +1,9 @@
 # consumers
-FactoryGirl.create(:consumer)
-FactoryGirl.create(:consumer, name: 'openSAP')
+FactoryBot.create(:consumer)
+FactoryBot.create(:consumer, name: 'openSAP')
 
 # users
-[:admin, :external_user, :teacher].each { |factory_name| FactoryGirl.create(factory_name) }
+[:admin, :external_user, :teacher].each { |factory_name| FactoryBot.create(factory_name) }
 
 # execution environments
 ExecutionEnvironment.create_factories
@@ -12,7 +12,7 @@ ExecutionEnvironment.create_factories
 Error.create_factories
 
 # exercises
-@exercises = find_factories_by_class(Exercise).map(&:name).map { |factory_name| [factory_name, FactoryGirl.create(factory_name)] }.to_h
+@exercises = find_factories_by_class(Exercise).map(&:name).map { |factory_name| [factory_name, FactoryBot.create(factory_name)] }.to_h
 
 # file types
 FileType.create_factories
@@ -21,4 +21,4 @@ FileType.create_factories
 Hint.create_factories
 
 # submissions
-FactoryGirl.create(:submission, exercise: @exercises[:fibonacci])
+FactoryBot.create(:submission, exercise: @exercises[:fibonacci])
diff --git a/db/seeds/production.rb b/db/seeds/production.rb
index 301becfd..5b63f57b 100644
--- a/db/seeds/production.rb
+++ b/db/seeds/production.rb
@@ -1,7 +1,7 @@
 require 'highline/import'
 
 # consumers
-FactoryGirl.create(:consumer)
+FactoryBot.create(:consumer)
 
 # users
 email = ask('Enter admin email: ')
@@ -11,7 +11,7 @@ passwords = ['password', 'password confirmation'].map do |attribute|
 end
 
 if passwords.uniq.length == 1
-  FactoryGirl.create(:admin, email: email, name: 'Administrator', password: passwords.first)
+  FactoryBot.create(:admin, email: email, name: 'Administrator', password: passwords.first)
 else
   abort('Passwords do not match!')
 end
diff --git a/lib/xikolo/client.rb b/lib/xikolo/client.rb
deleted file mode 100644
index 4e6f22b2..00000000
--- a/lib/xikolo/client.rb
+++ /dev/null
@@ -1,59 +0,0 @@
-class Xikolo::Client
-  def self.get_user(user_id)
-    params = {:user_id => user_id}
-    response = get_request(user_profile_url(user_id), params)
-    if response
-      return JSON.parse(response)
-    else
-      return nil
-    end
-  end
-
-  def self.user_profile_url(user_id)
-    return url + 'v2/users/' + user_id
-  end
-
-  def self.post_request(url, params)
-    begin
-      return RestClient.post url, params, http_header
-    rescue
-      return nil
-    end
-  end
-
-  def self.get_request(url, params)
-    begin
-      return RestClient.get url, {:params => params}.merge(http_header)
-    rescue
-      return nil
-    end
-  end
-
-  def self.http_header
-    return {:accept => accept, :authorization => token}
-  end
-
-  def self.url
-    @url ||= CodeOcean::Config.new(:code_ocean).read.fetch(:xikolo_api_url, 'http://localhost:3000/api/') #caches this with ||=, second value of fetch is default value
-  end
-
-  def self.accept
-    'application/vnd.xikolo.v1, application/vnd.api+json, application/json'
-  end
-
-  def self.token
-    'Token token='+Rails.application.secrets.openhpi_api_token#+'"'
-  end
-
-  private
-
-  def authenticate_with_user
-    params = {:email => "admin@openhpi.de", :password => "admin"}
-    response = post_request(authentication_url, params)
-    @token = 'Token token="'+JSON.parse(response)['token']+'"'
-  end
-
-  def self.authentication_url
-    return @url + 'authenticate'
-  end
-end
\ No newline at end of file
diff --git a/lib/xikolo/user_client.rb b/lib/xikolo/user_client.rb
deleted file mode 100644
index c681c999..00000000
--- a/lib/xikolo/user_client.rb
+++ /dev/null
@@ -1,15 +0,0 @@
-class Xikolo::UserClient
-  def self.get(user_id)
-    user = Xikolo::Client.get_user(user_id)
-
-    # return default values if user is not found or if there is a server issue:
-    if user
-      name = user.dig('data', 'attributes', 'name') || "User "  + user_id
-      user_visual = user.dig('data', 'attributes', 'avatar_url') || ActionController::Base.helpers.image_path('default.png')
-      language = user.dig('data', 'attributes', 'language') || "DE"
-      return {display_name: name, user_visual: user_visual, language: language}
-    else
-      return {display_name: "User " + user_id, user_visual: ActionController::Base.helpers.image_path('default.png'), language: "DE"}
-    end
-  end
-end
\ No newline at end of file
diff --git a/spec/concerns/lti_spec.rb b/spec/concerns/lti_spec.rb
index 32d740aa..a7b1dfcc 100644
--- a/spec/concerns/lti_spec.rb
+++ b/spec/concerns/lti_spec.rb
@@ -11,7 +11,7 @@ describe Lti do
   describe '#build_tool_provider' do
     it 'instantiates a tool provider' do
       expect(IMS::LTI::ToolProvider).to receive(:new)
-      controller.send(:build_tool_provider, consumer: FactoryGirl.build(:consumer), parameters: {})
+      controller.send(:build_tool_provider, consumer: FactoryBot.build(:consumer), parameters: {})
     end
   end
 
@@ -95,10 +95,10 @@ describe Lti do
   end
 
   describe '#send_score' do
-    let(:consumer) { FactoryGirl.create(:consumer) }
+    let(:consumer) { FactoryBot.create(:consumer) }
     let(:score) { 0.5 }
-    let(:submission) { FactoryGirl.create(:submission) }
-    let!(:lti_parameter) { FactoryGirl.create(:lti_parameter)}
+    let(:submission) { FactoryBot.create(:submission) }
+    let!(:lti_parameter) { FactoryBot.create(:lti_parameter)}
 
     context 'with an invalid score' do
       it 'raises an exception' do
@@ -159,18 +159,18 @@ describe Lti do
     let(:parameters) { {} }
 
     it 'stores data in the session' do
-      controller.instance_variable_set(:@current_user, FactoryGirl.create(:external_user))
-      controller.instance_variable_set(:@exercise, FactoryGirl.create(:fibonacci))
+      controller.instance_variable_set(:@current_user, FactoryBot.create(:external_user))
+      controller.instance_variable_set(:@exercise, FactoryBot.create(:fibonacci))
       expect(controller.session).to receive(:[]=).with(:consumer_id, anything)
       expect(controller.session).to receive(:[]=).with(:external_user_id, anything)
-      controller.send(:store_lti_session_data, consumer: FactoryGirl.build(:consumer), parameters: parameters)
+      controller.send(:store_lti_session_data, consumer: FactoryBot.build(:consumer), parameters: parameters)
     end
 
     it 'it creates an LtiParameter Object' do
       before_count = LtiParameter.count
-      controller.instance_variable_set(:@current_user, FactoryGirl.create(:external_user))
-      controller.instance_variable_set(:@exercise, FactoryGirl.create(:fibonacci))
-      controller.send(:store_lti_session_data, consumer: FactoryGirl.build(:consumer), parameters: parameters)
+      controller.instance_variable_set(:@current_user, FactoryBot.create(:external_user))
+      controller.instance_variable_set(:@exercise, FactoryBot.create(:fibonacci))
+      controller.send(:store_lti_session_data, consumer: FactoryBot.build(:consumer), parameters: parameters)
       expect(LtiParameter.count).to eq(before_count + 1)
     end
   end
diff --git a/spec/concerns/submission_scoring_spec.rb b/spec/concerns/submission_scoring_spec.rb
index 1b42a947..c32fe9c3 100644
--- a/spec/concerns/submission_scoring_spec.rb
+++ b/spec/concerns/submission_scoring_spec.rb
@@ -6,8 +6,8 @@ end
 
 describe SubmissionScoring do
   let(:controller) { Controller.new }
-  before(:all) { @submission = FactoryGirl.create(:submission, cause: 'submit') }
-  before(:each) { controller.instance_variable_set(:@current_user, FactoryGirl.create(:external_user)) }
+  before(:all) { @submission = FactoryBot.create(:submission, cause: 'submit') }
+  before(:each) { controller.instance_variable_set(:@current_user, FactoryBot.create(:external_user)) }
 
   describe '#collect_test_results' do
     after(:each) { controller.send(:collect_test_results, @submission) }
diff --git a/spec/controllers/admin/dashboard_controller_spec.rb b/spec/controllers/admin/dashboard_controller_spec.rb
index d62bb0ee..20265e16 100644
--- a/spec/controllers/admin/dashboard_controller_spec.rb
+++ b/spec/controllers/admin/dashboard_controller_spec.rb
@@ -1,7 +1,7 @@
 require 'rails_helper'
 
 describe Admin::DashboardController do
-  before(:each) { allow(controller).to receive(:current_user).and_return(FactoryGirl.build(:admin)) }
+  before(:each) { allow(controller).to receive(:current_user).and_return(FactoryBot.build(:admin)) }
 
   describe 'GET #show' do
     describe 'with format HTML' do
diff --git a/spec/controllers/application_controller_spec.rb b/spec/controllers/application_controller_spec.rb
index 0ad4b20d..eec0abbe 100644
--- a/spec/controllers/application_controller_spec.rb
+++ b/spec/controllers/application_controller_spec.rb
@@ -3,7 +3,7 @@ require 'rails_helper'
 describe ApplicationController do
   describe '#current_user' do
     context 'with an external user' do
-      let(:external_user) { FactoryGirl.create(:external_user) }
+      let(:external_user) { FactoryBot.create(:external_user) }
       before(:each) { session[:external_user_id] = external_user.id }
 
       it 'returns the external user' do
@@ -12,7 +12,7 @@ describe ApplicationController do
     end
 
     context 'without an external user' do
-      let(:internal_user) { FactoryGirl.create(:teacher) }
+      let(:internal_user) { FactoryBot.create(:teacher) }
       before(:each) { login_user(internal_user) }
 
       it 'returns the internal user' do
diff --git a/spec/controllers/code_ocean/files_controller_spec.rb b/spec/controllers/code_ocean/files_controller_spec.rb
index 08062acb..9bed884b 100644
--- a/spec/controllers/code_ocean/files_controller_spec.rb
+++ b/spec/controllers/code_ocean/files_controller_spec.rb
@@ -1,14 +1,14 @@
 require 'rails_helper'
 
 describe CodeOcean::FilesController do
-  let(:user) { FactoryGirl.create(:admin) }
+  let(:user) { FactoryBot.create(:admin) }
   before(:each) { allow(controller).to receive(:current_user).and_return(user) }
 
   describe 'POST #create' do
-    let(:submission) { FactoryGirl.create(:submission, user: user) }
+    let(:submission) { FactoryBot.create(:submission, user: user) }
 
     context 'with a valid file' do
-      let(:request) { proc { post :create, code_ocean_file: FactoryGirl.build(:file, context: submission).attributes, format: :json } }
+      let(:request) { proc { post :create, code_ocean_file: FactoryBot.build(:file, context: submission).attributes, format: :json } }
       before(:each) { request.call }
 
       expect_assigns(file: CodeOcean::File)
@@ -31,14 +31,14 @@ describe CodeOcean::FilesController do
   end
 
   describe 'DELETE #destroy' do
-    let(:exercise) { FactoryGirl.create(:fibonacci) }
+    let(:exercise) { FactoryBot.create(:fibonacci) }
     let(:request) { proc { delete :destroy, id: exercise.files.first.id } }
     before(:each) { request.call }
 
     expect_assigns(file: CodeOcean::File)
 
     it 'destroys the file' do
-      FactoryGirl.create(:fibonacci)
+      FactoryBot.create(:fibonacci)
       expect { request.call }.to change(CodeOcean::File, :count).by(-1)
     end
 
diff --git a/spec/controllers/consumers_controller_spec.rb b/spec/controllers/consumers_controller_spec.rb
index 1060c845..448f13dc 100644
--- a/spec/controllers/consumers_controller_spec.rb
+++ b/spec/controllers/consumers_controller_spec.rb
@@ -1,13 +1,13 @@
 require 'rails_helper'
 
 describe ConsumersController do
-  let(:consumer) { FactoryGirl.create(:consumer) }
-  let(:user) { FactoryGirl.create(:admin) }
+  let(:consumer) { FactoryBot.create(:consumer) }
+  let(:user) { FactoryBot.create(:admin) }
   before(:each) { allow(controller).to receive(:current_user).and_return(user) }
 
   describe 'POST #create' do
     context 'with a valid consumer' do
-      let(:request) { proc { post :create, consumer: FactoryGirl.attributes_for(:consumer) } }
+      let(:request) { proc { post :create, consumer: FactoryBot.attributes_for(:consumer) } }
       before(:each) { request.call }
 
       expect_assigns(consumer: Consumer)
@@ -34,7 +34,7 @@ describe ConsumersController do
     expect_assigns(consumer: Consumer)
 
     it 'destroys the consumer' do
-      consumer = FactoryGirl.create(:consumer)
+      consumer = FactoryBot.create(:consumer)
       expect { delete :destroy, id: consumer.id }.to change(Consumer, :count).by(-1)
     end
 
@@ -50,7 +50,7 @@ describe ConsumersController do
   end
 
   describe 'GET #index' do
-    let!(:consumers) { FactoryGirl.create_pair(:consumer) }
+    let!(:consumers) { FactoryBot.create_pair(:consumer) }
     before(:each) { get :index }
 
     expect_assigns(consumers: Consumer.all)
@@ -76,7 +76,7 @@ describe ConsumersController do
 
   describe 'PUT #update' do
     context 'with a valid consumer' do
-      before(:each) { put :update, consumer: FactoryGirl.attributes_for(:consumer), id: consumer.id }
+      before(:each) { put :update, consumer: FactoryBot.attributes_for(:consumer), id: consumer.id }
 
       expect_assigns(consumer: Consumer)
       expect_redirect(:consumer)
diff --git a/spec/controllers/execution_environments_controller_spec.rb b/spec/controllers/execution_environments_controller_spec.rb
index 2abf59ef..ee9ba3d5 100644
--- a/spec/controllers/execution_environments_controller_spec.rb
+++ b/spec/controllers/execution_environments_controller_spec.rb
@@ -1,15 +1,15 @@
 require 'rails_helper'
 
 describe ExecutionEnvironmentsController do
-  let(:execution_environment) { FactoryGirl.create(:ruby) }
-  let(:user) { FactoryGirl.create(:admin) }
+  let(:execution_environment) { FactoryBot.create(:ruby) }
+  let(:user) { FactoryBot.create(:admin) }
   before(:each) { allow(controller).to receive(:current_user).and_return(user) }
 
   describe 'POST #create' do
     before(:each) { expect(DockerClient).to receive(:image_tags).at_least(:once).and_return([]) }
 
     context 'with a valid execution environment' do
-      let(:request) { proc { post :create, execution_environment: FactoryGirl.attributes_for(:ruby) } }
+      let(:request) { proc { post :create, execution_environment: FactoryBot.attributes_for(:ruby) } }
       before(:each) { request.call }
 
       expect_assigns(docker_images: Array)
@@ -37,7 +37,7 @@ describe ExecutionEnvironmentsController do
     expect_assigns(execution_environment: :execution_environment)
 
     it 'destroys the execution environment' do
-      execution_environment = FactoryGirl.create(:ruby)
+      execution_environment = FactoryBot.create(:ruby)
       expect { delete :destroy, id: execution_environment.id }.to change(ExecutionEnvironment, :count).by(-1)
     end
 
@@ -72,7 +72,7 @@ describe ExecutionEnvironmentsController do
   end
 
   describe 'GET #index' do
-    before(:all) { FactoryGirl.create_pair(:ruby) }
+    before(:all) { FactoryBot.create_pair(:ruby) }
     before(:each) { get :index }
 
     expect_assigns(execution_environments: ExecutionEnvironment.all)
@@ -150,7 +150,7 @@ describe ExecutionEnvironmentsController do
     context 'with a valid execution environment' do
       before(:each) do
         expect(DockerClient).to receive(:image_tags).at_least(:once).and_return([])
-        put :update, execution_environment: FactoryGirl.attributes_for(:ruby), id: execution_environment.id
+        put :update, execution_environment: FactoryBot.attributes_for(:ruby), id: execution_environment.id
       end
 
       expect_assigns(docker_images: Array)
diff --git a/spec/controllers/exercises_controller_spec.rb b/spec/controllers/exercises_controller_spec.rb
index 43dada43..f1d5db96 100644
--- a/spec/controllers/exercises_controller_spec.rb
+++ b/spec/controllers/exercises_controller_spec.rb
@@ -1,8 +1,8 @@
 require 'rails_helper'
 
 describe ExercisesController do
-  let(:exercise) { FactoryGirl.create(:dummy) }
-  let(:user) { FactoryGirl.create(:admin) }
+  let(:exercise) { FactoryBot.create(:dummy) }
+  let(:user) { FactoryBot.create(:admin) }
   before(:each) { allow(controller).to receive(:current_user).and_return(user) }
 
   describe 'PUT #batch_update' do
@@ -52,7 +52,7 @@ describe ExercisesController do
   end
 
   describe 'POST #create' do
-    let(:exercise_attributes) { FactoryGirl.build(:dummy).attributes }
+    let(:exercise_attributes) { FactoryBot.build(:dummy).attributes }
 
     context 'with a valid exercise' do
       let(:request) { proc { post :create, exercise: exercise_attributes } }
@@ -71,7 +71,7 @@ describe ExercisesController do
       let(:request) { proc { post :create, exercise: exercise_attributes.merge(files_attributes: files_attributes) } }
 
       context 'when specifying the file content within the form' do
-        let(:files_attributes) { {'0' => FactoryGirl.build(:file).attributes} }
+        let(:files_attributes) { {'0' => FactoryBot.build(:file).attributes} }
 
         it 'creates the file' do
           expect { request.call }.to change(CodeOcean::File, :count)
@@ -79,11 +79,11 @@ describe ExercisesController do
       end
 
       context 'when uploading a file' do
-        let(:files_attributes) { {'0' => FactoryGirl.build(:file, file_type: file_type).attributes.merge(content: uploaded_file)} }
+        let(:files_attributes) { {'0' => FactoryBot.build(:file, file_type: file_type).attributes.merge(content: uploaded_file)} }
 
         context 'when uploading a binary file' do
           let(:file_path) { Rails.root.join('db', 'seeds', 'audio_video', 'devstories.mp4') }
-          let(:file_type) { FactoryGirl.create(:dot_mp4) }
+          let(:file_type) { FactoryBot.create(:dot_mp4) }
           let(:uploaded_file) { Rack::Test::UploadedFile.new(file_path, 'video/mp4', true) }
 
           it 'creates the file' do
@@ -98,7 +98,7 @@ describe ExercisesController do
 
         context 'when uploading a non-binary file' do
           let(:file_path) { Rails.root.join('db', 'seeds', 'fibonacci', 'exercise.rb') }
-          let(:file_type) { FactoryGirl.create(:dot_rb) }
+          let(:file_type) { FactoryBot.create(:dot_rb) }
           let(:uploaded_file) { Rack::Test::UploadedFile.new(file_path, 'text/x-ruby', false) }
 
           it 'creates the file' do
@@ -128,7 +128,7 @@ describe ExercisesController do
     expect_assigns(exercise: :exercise)
 
     it 'destroys the exercise' do
-      exercise = FactoryGirl.create(:dummy)
+      exercise = FactoryBot.create(:dummy)
       expect { delete :destroy, id: exercise.id }.to change(Exercise, :count).by(-1)
     end
 
@@ -147,13 +147,13 @@ describe ExercisesController do
     let(:request) { proc { get :implement, id: exercise.id } }
 
     context 'with an exercise with visible files' do
-      let(:exercise) { FactoryGirl.create(:fibonacci) }
+      let(:exercise) { FactoryBot.create(:fibonacci) }
       before(:each) { request.call }
 
       expect_assigns(exercise: :exercise)
 
       context 'with an existing submission' do
-        let!(:submission) { FactoryGirl.create(:submission, exercise_id: exercise.id, user_id: user.id, user_type: user.class.name) }
+        let!(:submission) { FactoryBot.create(:submission, exercise_id: exercise.id, user_id: user.id, user_type: user.class.name) }
 
         it "populates the editors with the submission's files' content" do
           request.call
@@ -182,7 +182,7 @@ describe ExercisesController do
 
   describe 'GET #index' do
     let(:scope) { Pundit.policy_scope!(user, Exercise) }
-    before(:all) { FactoryGirl.create_pair(:dummy) }
+    before(:all) { FactoryBot.create_pair(:dummy) }
     before(:each) { get :index }
 
     expect_assigns(exercises: :scope)
@@ -230,8 +230,8 @@ describe ExercisesController do
   describe 'POST #submit' do
     let(:output) { {} }
     let(:request) { post :submit, format: :json, id: exercise.id, submission: {cause: 'submit', exercise_id: exercise.id} }
-    let!(:external_user) { FactoryGirl.create(:external_user) }
-    let!(:lti_parameter) { FactoryGirl.create(:lti_parameter, external_user: external_user, exercise: exercise) }
+    let!(:external_user) { FactoryBot.create(:external_user) }
+    let!(:lti_parameter) { FactoryBot.create(:lti_parameter, external_user: external_user, exercise: exercise) }
 
     before(:each) do
       allow_any_instance_of(Submission).to receive(:normalized_score).and_return(1)
@@ -298,7 +298,7 @@ describe ExercisesController do
 
   describe 'PUT #update' do
     context 'with a valid exercise' do
-      let(:exercise_attributes) { FactoryGirl.build(:dummy).attributes }
+      let(:exercise_attributes) { FactoryBot.build(:dummy).attributes }
       before(:each) { put :update, exercise: exercise_attributes, id: exercise.id }
 
       expect_assigns(exercise: Exercise)
diff --git a/spec/controllers/external_users_controller_spec.rb b/spec/controllers/external_users_controller_spec.rb
index b3029e6e..c8df8da7 100644
--- a/spec/controllers/external_users_controller_spec.rb
+++ b/spec/controllers/external_users_controller_spec.rb
@@ -1,8 +1,8 @@
 require 'rails_helper'
 
 describe ExternalUsersController do
-  let(:user) { FactoryGirl.build(:admin) }
-  let!(:users) { FactoryGirl.create_pair(:external_user) }
+  let(:user) { FactoryBot.build(:admin) }
+  let!(:users) { FactoryBot.create_pair(:external_user) }
   before(:each) { allow(controller).to receive(:current_user).and_return(user) }
 
   describe 'GET #index' do
diff --git a/spec/controllers/file_types_controller_spec.rb b/spec/controllers/file_types_controller_spec.rb
index 037e5ae5..83e8396b 100644
--- a/spec/controllers/file_types_controller_spec.rb
+++ b/spec/controllers/file_types_controller_spec.rb
@@ -1,13 +1,13 @@
 require 'rails_helper'
 
 describe FileTypesController do
-  let(:file_type) { FactoryGirl.create(:dot_rb) }
-  let(:user) { FactoryGirl.create(:admin) }
+  let(:file_type) { FactoryBot.create(:dot_rb) }
+  let(:user) { FactoryBot.create(:admin) }
   before(:each) { allow(controller).to receive(:current_user).and_return(user) }
 
   describe 'POST #create' do
     context 'with a valid file type' do
-      let(:request) { proc { post :create, file_type: FactoryGirl.attributes_for(:dot_rb) } }
+      let(:request) { proc { post :create, file_type: FactoryBot.attributes_for(:dot_rb) } }
       before(:each) { request.call }
 
       expect_assigns(editor_modes: Array)
@@ -36,7 +36,7 @@ describe FileTypesController do
     expect_assigns(file_type: FileType)
 
     it 'destroys the file type' do
-      file_type = FactoryGirl.create(:dot_rb)
+      file_type = FactoryBot.create(:dot_rb)
       expect { delete :destroy, id: file_type.id }.to change(FileType, :count).by(-1)
     end
 
@@ -53,7 +53,7 @@ describe FileTypesController do
   end
 
   describe 'GET #index' do
-    before(:all) { FactoryGirl.create_pair(:dot_rb) }
+    before(:all) { FactoryBot.create_pair(:dot_rb) }
     before(:each) { get :index }
 
     expect_assigns(file_types: FileType.all)
@@ -80,7 +80,7 @@ describe FileTypesController do
 
   describe 'PUT #update' do
     context 'with a valid file type' do
-      before(:each) { put :update, file_type: FactoryGirl.attributes_for(:dot_rb), id: file_type.id }
+      before(:each) { put :update, file_type: FactoryBot.attributes_for(:dot_rb), id: file_type.id }
 
       expect_assigns(editor_modes: Array)
       expect_assigns(file_type: FileType)
diff --git a/spec/controllers/hints_controller_spec.rb b/spec/controllers/hints_controller_spec.rb
index 916e5150..f54d09ad 100644
--- a/spec/controllers/hints_controller_spec.rb
+++ b/spec/controllers/hints_controller_spec.rb
@@ -1,14 +1,14 @@
 require 'rails_helper'
 
 describe HintsController do
-  let(:execution_environment) { FactoryGirl.create(:ruby) }
-  let(:hint) { FactoryGirl.create(:ruby_syntax_error) }
-  let(:user) { FactoryGirl.create(:admin) }
+  let(:execution_environment) { FactoryBot.create(:ruby) }
+  let(:hint) { FactoryBot.create(:ruby_syntax_error) }
+  let(:user) { FactoryBot.create(:admin) }
   before(:each) { allow(controller).to receive(:current_user).and_return(user) }
 
   describe 'POST #create' do
     context 'with a valid hint' do
-      let(:request) { proc { post :create, execution_environment_id: execution_environment.id, hint: FactoryGirl.attributes_for(:ruby_syntax_error) } }
+      let(:request) { proc { post :create, execution_environment_id: execution_environment.id, hint: FactoryBot.attributes_for(:ruby_syntax_error) } }
       before(:each) { request.call }
 
       expect_assigns(execution_environment: :execution_environment)
@@ -38,7 +38,7 @@ describe HintsController do
     expect_assigns(hint: Hint)
 
     it 'destroys the hint' do
-      hint = FactoryGirl.create(:ruby_syntax_error)
+      hint = FactoryBot.create(:ruby_syntax_error)
       expect { delete :destroy, execution_environment_id: execution_environment.id, id: hint.id }.to change(Hint, :count).by(-1)
     end
 
@@ -55,7 +55,7 @@ describe HintsController do
   end
 
   describe 'GET #index' do
-    before(:all) { FactoryGirl.create_pair(:ruby_syntax_error) }
+    before(:all) { FactoryBot.create_pair(:ruby_syntax_error) }
     before(:each) { get :index, execution_environment_id: execution_environment.id }
 
     expect_assigns(execution_environment: :execution_environment)
@@ -84,7 +84,7 @@ describe HintsController do
 
   describe 'PUT #update' do
     context 'with a valid hint' do
-      before(:each) { put :update, execution_environment_id: execution_environment.id, hint: FactoryGirl.attributes_for(:ruby_syntax_error), id: hint.id }
+      before(:each) { put :update, execution_environment_id: execution_environment.id, hint: FactoryBot.attributes_for(:ruby_syntax_error), id: hint.id }
 
       expect_assigns(execution_environment: :execution_environment)
       expect_assigns(hint: Hint)
diff --git a/spec/controllers/internal_users_controller_spec.rb b/spec/controllers/internal_users_controller_spec.rb
index e0efb339..936852af 100644
--- a/spec/controllers/internal_users_controller_spec.rb
+++ b/spec/controllers/internal_users_controller_spec.rb
@@ -1,11 +1,11 @@
 require 'rails_helper'
 
 describe InternalUsersController do
-  let(:user) { FactoryGirl.build(:admin) }
-  let!(:users) { FactoryGirl.create_pair(:teacher) }
+  let(:user) { FactoryBot.build(:admin) }
+  let!(:users) { FactoryBot.create_pair(:teacher) }
 
   describe 'GET #activate' do
-    let(:user) { InternalUser.create(FactoryGirl.attributes_for(:teacher)) }
+    let(:user) { InternalUser.create(FactoryBot.attributes_for(:teacher)) }
 
     before(:each) do
       user.send(:setup_activation)
@@ -37,7 +37,7 @@ describe InternalUsersController do
   end
 
   describe 'PUT #activate' do
-    let(:user) { InternalUser.create(FactoryGirl.attributes_for(:teacher)) }
+    let(:user) { InternalUser.create(FactoryBot.attributes_for(:teacher)) }
     let(:password) { SecureRandom.hex }
 
     before(:each) do
@@ -103,7 +103,7 @@ describe InternalUsersController do
     before(:each) { allow(controller).to receive(:current_user).and_return(user) }
 
     context 'with a valid internal user' do
-      let(:request) { proc { post :create, internal_user: FactoryGirl.attributes_for(:teacher) } }
+      let(:request) { proc { post :create, internal_user: FactoryBot.attributes_for(:teacher) } }
       before(:each) { request.call }
 
       expect_assigns(user: InternalUser)
@@ -303,7 +303,7 @@ describe InternalUsersController do
     before(:each) { allow(controller).to receive(:current_user).and_return(user) }
 
     context 'with a valid internal user' do
-      before(:each) { put :update, internal_user: FactoryGirl.attributes_for(:teacher), id: users.first.id }
+      before(:each) { put :update, internal_user: FactoryBot.attributes_for(:teacher), id: users.first.id }
 
       expect_assigns(user: InternalUser)
       expect_redirect { user }
diff --git a/spec/controllers/sessions_controller_spec.rb b/spec/controllers/sessions_controller_spec.rb
index 50fef8d6..480530da 100644
--- a/spec/controllers/sessions_controller_spec.rb
+++ b/spec/controllers/sessions_controller_spec.rb
@@ -1,12 +1,12 @@
 require 'rails_helper'
 
 describe SessionsController do
-  let(:consumer) { FactoryGirl.create(:consumer) }
+  let(:consumer) { FactoryBot.create(:consumer) }
 
   describe 'POST #create' do
     let(:password) { user_attributes[:password] }
     let(:user) { InternalUser.create(user_attributes) }
-    let(:user_attributes) { FactoryGirl.attributes_for(:teacher) }
+    let(:user_attributes) { FactoryBot.attributes_for(:teacher) }
 
     context 'with valid credentials' do
       before(:each) do
@@ -27,8 +27,8 @@ describe SessionsController do
   end
 
   describe 'POST #create_through_lti' do
-    let(:exercise) { FactoryGirl.create(:dummy) }
-    let(:exercise2) { FactoryGirl.create(:dummy) }
+    let(:exercise) { FactoryBot.create(:dummy) }
+    let(:exercise2) { FactoryBot.create(:dummy) }
     let(:nonce) { SecureRandom.hex }
     before(:each) { I18n.locale = I18n.default_locale }
 
@@ -73,7 +73,7 @@ describe SessionsController do
     context 'with valid launch parameters' do
       let(:locale) { :de }
       let(:request) { post :create_through_lti, custom_locale: locale, custom_token: exercise.token, oauth_consumer_key: consumer.oauth_key, oauth_nonce: nonce, oauth_signature: SecureRandom.hex, user_id: user.external_id }
-      let(:user) { FactoryGirl.create(:external_user, consumer_id: consumer.id) }
+      let(:user) { FactoryBot.create(:external_user, consumer_id: consumer.id) }
       before(:each) { expect_any_instance_of(IMS::LTI::ToolProvider).to receive(:valid_request?).and_return(true) }
 
       it 'assigns the current user' do
@@ -132,14 +132,14 @@ describe SessionsController do
       end
 
       it 'redirects to recommended exercise if requested token of proxy exercise' do
-        FactoryGirl.create(:proxy_exercise, exercises: [exercise])
+        FactoryBot.create(:proxy_exercise, exercises: [exercise])
         post :create_through_lti, custom_locale: locale, custom_token: ProxyExercise.first.token, oauth_consumer_key: consumer.oauth_key, oauth_nonce: nonce, oauth_signature: SecureRandom.hex, user_id: user.external_id
         expect(controller).to redirect_to(implement_exercise_path(exercise.id))
       end
 
       it 'recommends only exercises who are 1 degree more complicated than what user has seen' do
         # dummy user has no exercises finished, therefore his highest difficulty is 0
-        FactoryGirl.create(:proxy_exercise, exercises: [exercise, exercise2])
+        FactoryBot.create(:proxy_exercise, exercises: [exercise, exercise2])
         exercise.expected_difficulty = 3
         exercise.save
         exercise2.expected_difficulty = 1
@@ -191,7 +191,7 @@ describe SessionsController do
 
   describe 'GET #destroy_through_lti' do
     let(:request) { proc { get :destroy_through_lti, consumer_id: consumer.id, submission_id: submission.id } }
-    let(:submission) { FactoryGirl.create(:submission, exercise: FactoryGirl.create(:dummy)) }
+    let(:submission) { FactoryBot.create(:submission, exercise: FactoryBot.create(:dummy)) }
 
     before(:each) do
       #Todo replace session with lti_parameter
@@ -225,7 +225,7 @@ describe SessionsController do
 
     context 'when a user is already logged in' do
       before(:each) do
-        expect(controller).to receive(:current_user).and_return(FactoryGirl.build(:teacher))
+        expect(controller).to receive(:current_user).and_return(FactoryBot.build(:teacher))
         get :new
       end
 
diff --git a/spec/controllers/submissions_controller_spec.rb b/spec/controllers/submissions_controller_spec.rb
index 98f36cb2..2a3593c3 100644
--- a/spec/controllers/submissions_controller_spec.rb
+++ b/spec/controllers/submissions_controller_spec.rb
@@ -1,8 +1,8 @@
 require 'rails_helper'
 
 describe SubmissionsController do
-  let(:submission) { FactoryGirl.create(:submission) }
-  let(:user) { FactoryGirl.create(:admin) }
+  let(:submission) { FactoryBot.create(:submission) }
+  let(:user) { FactoryBot.create(:admin) }
   before(:each) { allow(controller).to receive(:current_user).and_return(user) }
 
   describe 'POST #create' do
@@ -11,8 +11,8 @@ describe SubmissionsController do
     end
 
     context 'with a valid submission' do
-      let(:exercise) { FactoryGirl.create(:hello_world) }
-      let(:request) { proc { post :create, format: :json, submission: FactoryGirl.attributes_for(:submission, exercise_id: exercise.id) } }
+      let(:exercise) { FactoryBot.create(:hello_world) }
+      let(:request) { proc { post :create, format: :json, submission: FactoryBot.attributes_for(:submission, exercise_id: exercise.id) } }
       before(:each) { request.call }
 
       expect_assigns(submission: Submission)
@@ -42,7 +42,7 @@ describe SubmissionsController do
     end
 
     context 'with a valid filename' do
-      let(:submission) { FactoryGirl.create(:submission, exercise: FactoryGirl.create(:audio_video)) }
+      let(:submission) { FactoryBot.create(:submission, exercise: FactoryBot.create(:audio_video)) }
       before(:each) { get :download_file, filename: file.name_with_extension, id: submission.id }
 
       context 'for a binary file' do
@@ -74,7 +74,7 @@ describe SubmissionsController do
   end
 
   describe 'GET #index' do
-    before(:all) { FactoryGirl.create_pair(:submission) }
+    before(:all) { FactoryBot.create_pair(:submission) }
     before(:each) { get :index }
 
     expect_assigns(submissions: Submission.all)
@@ -92,7 +92,7 @@ describe SubmissionsController do
     end
 
     context 'with a valid filename' do
-      let(:submission) { FactoryGirl.create(:submission, exercise: FactoryGirl.create(:audio_video)) }
+      let(:submission) { FactoryBot.create(:submission, exercise: FactoryBot.create(:audio_video)) }
       before(:each) { get :render_file, filename: file.name_with_extension, id: submission.id }
 
       context 'for a binary file' do
diff --git a/spec/factories/code_ocean/file.rb b/spec/factories/code_ocean/file.rb
index 663dc33f..bc672045 100644
--- a/spec/factories/code_ocean/file.rb
+++ b/spec/factories/code_ocean/file.rb
@@ -1,7 +1,7 @@
 require 'seeds_helper'
 
 module CodeOcean
-  FactoryGirl.define do
+  FactoryBot.define do
     factory :file, class: CodeOcean::File do
       content ''
       association :context, factory: :submission
diff --git a/spec/factories/consumer.rb b/spec/factories/consumer.rb
index 58bfbadc..a4f32ca8 100644
--- a/spec/factories/consumer.rb
+++ b/spec/factories/consumer.rb
@@ -1,4 +1,4 @@
-FactoryGirl.define do
+FactoryBot.define do
   factory :consumer do
     name 'openHPI'
     oauth_key { SecureRandom.hex }
diff --git a/spec/factories/error.rb b/spec/factories/error.rb
index 235a90c0..c10d47bf 100644
--- a/spec/factories/error.rb
+++ b/spec/factories/error.rb
@@ -1,4 +1,4 @@
-FactoryGirl.define do
+FactoryBot.define do
   factory :error, class: Error do
     association :execution_environment, factory: :ruby
     message "exercise.rb:4:in `<main>': undefined local variable or method `foo' for main:Object (NameError)"
diff --git a/spec/factories/execution_environment.rb b/spec/factories/execution_environment.rb
index 051d9de6..013a041b 100644
--- a/spec/factories/execution_environment.rb
+++ b/spec/factories/execution_environment.rb
@@ -1,4 +1,4 @@
-FactoryGirl.define do
+FactoryBot.define do
   factory :coffee_script, class: ExecutionEnvironment do
     created_by_teacher
     default_memory_limit
diff --git a/spec/factories/exercise.rb b/spec/factories/exercise.rb
index ea588faf..2fcd7e07 100644
--- a/spec/factories/exercise.rb
+++ b/spec/factories/exercise.rb
@@ -2,7 +2,7 @@ require 'seeds_helper'
 
 def create_seed_file(exercise, path, file_attributes = {})
   file_extension = File.extname(path)
-  file_type = FactoryGirl.create(file_attributes[:file_type] || :"dot_#{file_extension.gsub('.', '')}")
+  file_type = FactoryBot.create(file_attributes[:file_type] || :"dot_#{file_extension.gsub('.', '')}")
   name = File.basename(path).gsub(file_extension, '')
   file_attributes.merge!(file_type: file_type, name: name, path: path.split('/')[1..-2].join('/'), role: file_attributes[:role] || 'regular_file')
   if file_type.binary?
@@ -13,7 +13,7 @@ def create_seed_file(exercise, path, file_attributes = {})
   exercise.add_file!(file_attributes)
 end
 
-FactoryGirl.define do
+FactoryBot.define do
   factory :audio_video, class: Exercise do
     created_by_teacher
     description "Try HTML's audio and video capabilities."
@@ -38,6 +38,24 @@ FactoryGirl.define do
     association :execution_environment, factory: :ruby
     instructions
     title 'Dummy'
+
+    factory :dummy_with_user_feedbacks do
+      # user_feedbacks_count is declared as a transient attribute and available in
+      # attributes on the factory, as well as the callback via the evaluator
+      transient do
+        user_feedbacks_count 5
+      end
+
+      # the after(:create) yields two values; the exercise instance itself and the
+      # evaluator, which stores all values from the factory, including transient
+      # attributes; `create_list`'s second argument is the number of records
+      # to create and we make sure the user_exercise_feedback is associated properly to the exercise
+      after(:create) do |exercise, evaluator|
+        create_list(:user_exercise_feedback, evaluator.user_feedbacks_count, exercise: exercise)
+      end
+
+    end
+
   end
 
   factory :even_odd, class: Exercise do
diff --git a/spec/factories/external_user.rb b/spec/factories/external_user.rb
index 0d30796a..41a9c3e8 100644
--- a/spec/factories/external_user.rb
+++ b/spec/factories/external_user.rb
@@ -1,4 +1,4 @@
-FactoryGirl.define do
+FactoryBot.define do
   factory :external_user do
     association :consumer
     generated_email
diff --git a/spec/factories/file_type.rb b/spec/factories/file_type.rb
index 14b8e14e..eb7b8c90 100644
--- a/spec/factories/file_type.rb
+++ b/spec/factories/file_type.rb
@@ -1,4 +1,4 @@
-FactoryGirl.define do
+FactoryBot.define do
   factory :dot_coffee, class: FileType do
     created_by_admin
     editor_mode 'ace/mode/coffee'
diff --git a/spec/factories/hint.rb b/spec/factories/hint.rb
index 3f06babf..fa1335a9 100644
--- a/spec/factories/hint.rb
+++ b/spec/factories/hint.rb
@@ -1,4 +1,4 @@
-FactoryGirl.define do
+FactoryBot.define do
   factory :node_js_invalid_assignment, class: Hint do
     association :execution_environment, factory: :node_js
     english
diff --git a/spec/factories/internal_user.rb b/spec/factories/internal_user.rb
index f7311e4c..0e1c8682 100644
--- a/spec/factories/internal_user.rb
+++ b/spec/factories/internal_user.rb
@@ -1,4 +1,4 @@
-FactoryGirl.define do
+FactoryBot.define do
   factory :admin, class: InternalUser do
     activated_user
     email 'admin@example.org'
diff --git a/spec/factories/lti_parameter.rb b/spec/factories/lti_parameter.rb
index 9cd0f367..0d882acc 100644
--- a/spec/factories/lti_parameter.rb
+++ b/spec/factories/lti_parameter.rb
@@ -1,4 +1,4 @@
-FactoryGirl.define do
+FactoryBot.define do
 
   LTI_PARAMETERS = {
       lis_result_sourcedid: "c2db0c7c-4411-4b27-a52b-ddfc3dc32065",
@@ -17,4 +17,4 @@ FactoryGirl.define do
       lti_parameters LTI_PARAMETERS.except(:lis_outcome_service_url)
     end
   end
-end
\ No newline at end of file
+end
diff --git a/spec/factories/proxy_exercise.rb b/spec/factories/proxy_exercise.rb
index 9c9974d6..303839a6 100644
--- a/spec/factories/proxy_exercise.rb
+++ b/spec/factories/proxy_exercise.rb
@@ -1,4 +1,4 @@
-FactoryGirl.define do
+FactoryBot.define do
   factory :proxy_exercise, class: ProxyExercise do
     token 'dummytoken'
     title 'Dummy'
diff --git a/spec/factories/shared_traits.rb b/spec/factories/shared_traits.rb
index ea39e926..43847e8c 100644
--- a/spec/factories/shared_traits.rb
+++ b/spec/factories/shared_traits.rb
@@ -1,4 +1,4 @@
-FactoryGirl.define do
+FactoryBot.define do
   [:admin, :external_user, :teacher].each do |factory_name|
     trait :"created_by_#{factory_name}" do
       association :user, factory: factory_name
diff --git a/spec/factories/submission.rb b/spec/factories/submission.rb
index cd4e34e1..f40a2a1f 100644
--- a/spec/factories/submission.rb
+++ b/spec/factories/submission.rb
@@ -1,4 +1,4 @@
-FactoryGirl.define do
+FactoryBot.define do
   factory :submission do
     cause 'save'
     created_by_external_user
diff --git a/spec/factories/user_exercise_feedback.rb b/spec/factories/user_exercise_feedback.rb
new file mode 100644
index 00000000..42c5d803
--- /dev/null
+++ b/spec/factories/user_exercise_feedback.rb
@@ -0,0 +1,7 @@
+FactoryBot.define do
+  factory :user_exercise_feedback, class: UserExerciseFeedback do
+    created_by_external_user
+    feedback_text 'Most suitable exercise ever'
+  end
+
+end
diff --git a/spec/features/authentication_spec.rb b/spec/features/authentication_spec.rb
index 8b85a64b..2a777dab 100644
--- a/spec/features/authentication_spec.rb
+++ b/spec/features/authentication_spec.rb
@@ -1,8 +1,8 @@
 require 'rails_helper'
 
 describe 'Authentication' do
-  let(:user) { FactoryGirl.create(:admin) }
-  let(:password) { FactoryGirl.attributes_for(:admin)[:password] }
+  let(:user) { FactoryBot.create(:admin) }
+  let(:password) { FactoryBot.attributes_for(:admin)[:password] }
 
   context 'when signed out' do
     before(:each) { visit(root_path) }
diff --git a/spec/features/authorization_spec.rb b/spec/features/authorization_spec.rb
index 7f0ff04f..7535634f 100644
--- a/spec/features/authorization_spec.rb
+++ b/spec/features/authorization_spec.rb
@@ -2,7 +2,7 @@ require 'rails_helper'
 
 describe 'Authorization' do
   context 'as an admin' do
-    let(:user) { FactoryGirl.create(:admin) }
+    let(:user) { FactoryBot.create(:admin) }
     before(:each) { allow_any_instance_of(ApplicationController).to receive(:current_user).and_return(user) }
 
     [Consumer, ExecutionEnvironment, Exercise, FileType, InternalUser].each do |model|
@@ -11,7 +11,7 @@ describe 'Authorization' do
   end
 
   context 'as an external user' do
-    let(:user) { FactoryGirl.create(:external_user) }
+    let(:user) { FactoryBot.create(:external_user) }
     before(:each) { allow_any_instance_of(ApplicationController).to receive(:current_user).and_return(user) }
 
     [Consumer, ExecutionEnvironment, Exercise, FileType, InternalUser].each do |model|
@@ -20,7 +20,7 @@ describe 'Authorization' do
   end
 
   context 'as a teacher' do
-    let(:user) { FactoryGirl.create(:teacher) }
+    let(:user) { FactoryBot.create(:teacher) }
     before(:each) { allow_any_instance_of(ApplicationController).to receive(:current_user).and_return(user) }
 
     [Consumer, InternalUser].each do |model|
diff --git a/spec/features/editor_spec.rb b/spec/features/editor_spec.rb
index bd1c46a2..88e480d4 100644
--- a/spec/features/editor_spec.rb
+++ b/spec/features/editor_spec.rb
@@ -1,13 +1,13 @@
 require 'rails_helper'
 
 describe 'Editor', js: true do
-  let(:exercise) { FactoryGirl.create(:audio_video, instructions: Forgery(:lorem_ipsum).sentence) }
-  let(:user) { FactoryGirl.create(:teacher) }
+  let(:exercise) { FactoryBot.create(:audio_video, instructions: Forgery(:lorem_ipsum).sentence) }
+  let(:user) { FactoryBot.create(:teacher) }
 
   before(:each) do
     visit(sign_in_path)
     fill_in('email', with: user.email)
-    fill_in('password', with: FactoryGirl.attributes_for(:teacher)[:password])
+    fill_in('password', with: FactoryBot.attributes_for(:teacher)[:password])
     click_button(I18n.t('sessions.new.link'))
     visit(implement_exercise_path(exercise))
   end
diff --git a/spec/features/factories_spec.rb b/spec/features/factories_spec.rb
index 5e002f91..cba0d735 100644
--- a/spec/features/factories_spec.rb
+++ b/spec/features/factories_spec.rb
@@ -2,6 +2,6 @@ require 'rails_helper'
 
 describe 'Factories' do
   it 'are all valid', docker: true, permitted_execution_time: 30 do
-    expect { FactoryGirl.lint }.not_to raise_error
+    expect { FactoryBot.lint }.not_to raise_error
   end
 end
diff --git a/spec/helpers/admin/dashboard_helper_spec.rb b/spec/helpers/admin/dashboard_helper_spec.rb
index a063c756..9dadaa54 100644
--- a/spec/helpers/admin/dashboard_helper_spec.rb
+++ b/spec/helpers/admin/dashboard_helper_spec.rb
@@ -8,7 +8,7 @@ describe Admin::DashboardHelper do
   end
 
   describe '#docker_data' do
-    before(:each) { FactoryGirl.create(:ruby) }
+    before(:each) { FactoryBot.create(:ruby) }
 
     it 'contains an entry for every execution environment' do
       expect(docker_data.length).to eq(ExecutionEnvironment.count)
diff --git a/spec/helpers/exercise_helper_spec.rb b/spec/helpers/exercise_helper_spec.rb
index 2fa9b331..7feb10ca 100644
--- a/spec/helpers/exercise_helper_spec.rb
+++ b/spec/helpers/exercise_helper_spec.rb
@@ -2,7 +2,7 @@ require 'rails_helper'
 
 describe ExerciseHelper do
   describe '#embedding_parameters' do
-    let(:exercise) { FactoryGirl.build(:dummy) }
+    let(:exercise) { FactoryBot.build(:dummy) }
 
     it 'contains the locale' do
       expect(embedding_parameters(exercise)).to start_with("locale=#{I18n.locale}")
diff --git a/spec/lib/assessor_spec.rb b/spec/lib/assessor_spec.rb
index 38edf8d5..ac726c3f 100644
--- a/spec/lib/assessor_spec.rb
+++ b/spec/lib/assessor_spec.rb
@@ -1,7 +1,7 @@
 require 'rails_helper'
 
 describe Assessor do
-  let(:assessor) { described_class.new(execution_environment: FactoryGirl.build(:ruby)) }
+  let(:assessor) { described_class.new(execution_environment: FactoryBot.build(:ruby)) }
 
   describe '#assess' do
     let(:assess) { assessor.assess(stdout: stdout) }
@@ -53,7 +53,7 @@ describe Assessor do
 
     context 'with an execution environment without a testing framework adapter' do
       it 'raises an error' do
-        expect { described_class.new(execution_environment: FactoryGirl.build(:ruby, testing_framework: nil)) }.to raise_error(Assessor::Error)
+        expect { described_class.new(execution_environment: FactoryBot.build(:ruby, testing_framework: nil)) }.to raise_error(Assessor::Error)
       end
     end
   end
diff --git a/spec/lib/docker_client_spec.rb b/spec/lib/docker_client_spec.rb
index feb457f6..5901c130 100644
--- a/spec/lib/docker_client_spec.rb
+++ b/spec/lib/docker_client_spec.rb
@@ -3,10 +3,10 @@ require 'seeds_helper'
 
 describe DockerClient, docker: true do
   let(:command) { 'whoami' }
-  let(:docker_client) { described_class.new(execution_environment: FactoryGirl.build(:java), user: FactoryGirl.build(:admin)) }
-  let(:execution_environment) { FactoryGirl.build(:java) }
+  let(:docker_client) { described_class.new(execution_environment: FactoryBot.build(:java), user: FactoryBot.build(:admin)) }
+  let(:execution_environment) { FactoryBot.build(:java) }
   let(:image) { double }
-  let(:submission) { FactoryGirl.create(:submission) }
+  let(:submission) { FactoryBot.create(:submission) }
   let(:workspace_path) { '/tmp' }
 
   describe '.check_availability!' do
@@ -146,7 +146,7 @@ describe DockerClient, docker: true do
   end
 
   describe '#create_workspace_file' do
-    let(:file) { FactoryGirl.build(:file, content: 'puts 42') }
+    let(:file) { FactoryBot.build(:file, content: 'puts 42') }
     let(:file_path) { File.join(workspace_path, file.name_with_extension) }
     after(:each) { File.delete(file_path) }
 
diff --git a/spec/lib/docker_container_pool_spec.rb b/spec/lib/docker_container_pool_spec.rb
index d419dd5a..1ff39657 100644
--- a/spec/lib/docker_container_pool_spec.rb
+++ b/spec/lib/docker_container_pool_spec.rb
@@ -9,7 +9,7 @@ describe DockerContainerPool do
   private :reload_class
 
   before(:each) do
-    @execution_environment = FactoryGirl.create(:ruby)
+    @execution_environment = FactoryBot.create(:ruby)
     reload_class
   end
 
diff --git a/spec/lib/file_tree_spec.rb b/spec/lib/file_tree_spec.rb
index 64995936..92a4deb0 100644
--- a/spec/lib/file_tree_spec.rb
+++ b/spec/lib/file_tree_spec.rb
@@ -8,7 +8,7 @@ describe FileTree do
 
     context 'for a media file' do
       context 'for an audio file' do
-        let(:file) { FactoryGirl.build(:file, file_type: FactoryGirl.build(:dot_mp3)) }
+        let(:file) { FactoryBot.build(:file, file_type: FactoryBot.build(:dot_mp3)) }
 
         it 'is an audio file icon' do
           expect(file_icon).to include('fa-file-audio-o')
@@ -16,7 +16,7 @@ describe FileTree do
       end
 
       context 'for an image file' do
-        let(:file) { FactoryGirl.build(:file, file_type: FactoryGirl.build(:dot_jpg)) }
+        let(:file) { FactoryBot.build(:file, file_type: FactoryBot.build(:dot_jpg)) }
 
         it 'is an image file icon' do
           expect(file_icon).to include('fa-file-image-o')
@@ -24,7 +24,7 @@ describe FileTree do
       end
 
       context 'for a video file' do
-        let(:file) { FactoryGirl.build(:file, file_type: FactoryGirl.build(:dot_mp4)) }
+        let(:file) { FactoryBot.build(:file, file_type: FactoryBot.build(:dot_mp4)) }
 
         it 'is a video file icon' do
           expect(file_icon).to include('fa-file-video-o')
@@ -34,7 +34,7 @@ describe FileTree do
 
     context 'for other files' do
       context 'for a read-only file' do
-        let(:file) { FactoryGirl.build(:file, read_only: true) }
+        let(:file) { FactoryBot.build(:file, read_only: true) }
 
         it 'is a lock icon' do
           expect(file_icon).to include('fa-lock')
@@ -42,7 +42,7 @@ describe FileTree do
       end
 
       context 'for an executable file' do
-        let(:file) { FactoryGirl.build(:file, file_type: FactoryGirl.build(:dot_py)) }
+        let(:file) { FactoryBot.build(:file, file_type: FactoryBot.build(:dot_py)) }
 
         it 'is a code file icon' do
           expect(file_icon).to include('fa-file-code-o')
@@ -50,7 +50,7 @@ describe FileTree do
       end
 
       context 'for a renderable file' do
-        let(:file) { FactoryGirl.build(:file, file_type: FactoryGirl.build(:dot_svg)) }
+        let(:file) { FactoryBot.build(:file, file_type: FactoryBot.build(:dot_svg)) }
 
         it 'is a text file icon' do
           expect(file_icon).to include('fa-file-text-o')
@@ -58,7 +58,7 @@ describe FileTree do
       end
 
       context 'for all other files' do
-        let(:file) { FactoryGirl.build(:file, file_type: FactoryGirl.build(:dot_md)) }
+        let(:file) { FactoryBot.build(:file, file_type: FactoryBot.build(:dot_md)) }
 
         it 'is a generic file icon' do
           expect(file_icon).to include('fa-file-o')
@@ -75,7 +75,7 @@ describe FileTree do
 
   describe '#initialize' do
     let(:file_tree) { described_class.new(files) }
-    let(:files) { FactoryGirl.build_list(:file, 10, context: nil, path: 'foo/bar/baz') }
+    let(:files) { FactoryBot.build_list(:file, 10, context: nil, path: 'foo/bar/baz') }
 
     it 'creates a root node' do
       expect_any_instance_of(Tree::TreeNode).to receive(:initialize).with(file_tree.send(:root_label))
@@ -92,7 +92,7 @@ describe FileTree do
   end
 
   describe '#map_to_js_tree' do
-    let(:file) { FactoryGirl.build(:file) }
+    let(:file) { FactoryBot.build(:file) }
     let(:js_tree) { file_tree.send(:map_to_js_tree, node) }
     let!(:leaf) { root.add(Tree::TreeNode.new('', file)) }
     let(:root) { Tree::TreeNode.new('', file) }
diff --git a/spec/lib/whistleblower_spec.rb b/spec/lib/whistleblower_spec.rb
index a7a7c9c6..e0a8a8d9 100644
--- a/spec/lib/whistleblower_spec.rb
+++ b/spec/lib/whistleblower_spec.rb
@@ -1,7 +1,7 @@
 require 'rails_helper'
 
 describe Whistleblower do
-  let(:hint) { FactoryGirl.create(:ruby_no_method_error) }
+  let(:hint) { FactoryBot.create(:ruby_no_method_error) }
   let(:stderr) { "undefined method `foo' for main:Object (NoMethodError)" }
   let(:whistleblower) { described_class.new(execution_environment: hint.execution_environment) }
 
diff --git a/spec/mailers/user_mailer_spec.rb b/spec/mailers/user_mailer_spec.rb
index b40b0728..d89b646c 100644
--- a/spec/mailers/user_mailer_spec.rb
+++ b/spec/mailers/user_mailer_spec.rb
@@ -1,7 +1,7 @@
 require 'rails_helper'
 
 describe UserMailer do
-  let(:user) { InternalUser.create(FactoryGirl.attributes_for(:teacher)) }
+  let(:user) { InternalUser.create(FactoryBot.attributes_for(:teacher)) }
 
   describe '#activation_needed_email' do
     let(:mail) { described_class.activation_needed_email(user) }
diff --git a/spec/models/consumer_spec.rb b/spec/models/consumer_spec.rb
index ed5e0fbe..0c977955 100644
--- a/spec/models/consumer_spec.rb
+++ b/spec/models/consumer_spec.rb
@@ -12,7 +12,7 @@ describe Consumer do
   end
 
   it 'validates the uniqueness of the OAuth key' do
-    consumer.update(oauth_key: FactoryGirl.create(:consumer).oauth_key)
+    consumer.update(oauth_key: FactoryBot.create(:consumer).oauth_key)
     expect(consumer.errors[:oauth_key]).to be_present
   end
 
diff --git a/spec/models/execution_environment_spec.rb b/spec/models/execution_environment_spec.rb
index a55eda25..fc119b38 100644
--- a/spec/models/execution_environment_spec.rb
+++ b/spec/models/execution_environment_spec.rb
@@ -6,7 +6,7 @@ describe ExecutionEnvironment do
   it 'validates that the Docker image works', docker: true do
     expect(execution_environment).to receive(:validate_docker_image?).and_return(true)
     expect(execution_environment).to receive(:working_docker_image?)
-    execution_environment.update(docker_image: FactoryGirl.attributes_for(:ruby)[:docker_image])
+    execution_environment.update(docker_image: FactoryBot.attributes_for(:ruby)[:docker_image])
   end
 
   it 'validates the presence of a Docker image name' do
@@ -69,7 +69,7 @@ describe ExecutionEnvironment do
 
   describe '#valid_test_setup?' do
     context 'with a test command and a testing framework' do
-      before(:each) { execution_environment.update(test_command: FactoryGirl.attributes_for(:ruby)[:test_command], testing_framework: FactoryGirl.attributes_for(:ruby)[:testing_framework]) }
+      before(:each) { execution_environment.update(test_command: FactoryBot.attributes_for(:ruby)[:test_command], testing_framework: FactoryBot.attributes_for(:ruby)[:testing_framework]) }
 
       it 'is valid' do
         expect(execution_environment.errors[:test_command]).to be_blank
@@ -77,7 +77,7 @@ describe ExecutionEnvironment do
     end
 
     context 'with a test command but no testing framework' do
-      before(:each) { execution_environment.update(test_command: FactoryGirl.attributes_for(:ruby)[:test_command], testing_framework: nil) }
+      before(:each) { execution_environment.update(test_command: FactoryBot.attributes_for(:ruby)[:test_command], testing_framework: nil) }
 
       it 'is invalid' do
         expect(execution_environment.errors[:test_command]).to be_present
@@ -85,7 +85,7 @@ describe ExecutionEnvironment do
     end
 
     context 'with no test command but a testing framework' do
-      before(:each) { execution_environment.update(test_command: nil, testing_framework: FactoryGirl.attributes_for(:ruby)[:testing_framework]) }
+      before(:each) { execution_environment.update(test_command: nil, testing_framework: FactoryBot.attributes_for(:ruby)[:testing_framework]) }
 
       it 'is invalid' do
         expect(execution_environment.errors[:test_command]).to be_present
@@ -113,7 +113,7 @@ describe ExecutionEnvironment do
     end
 
     it 'is true otherwise' do
-      execution_environment.docker_image = FactoryGirl.attributes_for(:ruby)[:docker_image]
+      execution_environment.docker_image = FactoryBot.attributes_for(:ruby)[:docker_image]
       allow(Rails.env).to receive(:test?).and_return(false)
       expect(execution_environment.send(:validate_docker_image?)).to be true
     end
diff --git a/spec/models/exercise_spec.rb b/spec/models/exercise_spec.rb
index f91ed4fa..640efd92 100644
--- a/spec/models/exercise_spec.rb
+++ b/spec/models/exercise_spec.rb
@@ -2,17 +2,17 @@ require 'rails_helper'
 
 describe Exercise do
   let(:exercise) { described_class.create.tap { |exercise| exercise.update(public: nil, token: nil) } }
-  let(:users) { FactoryGirl.create_list(:external_user, 10) }
+  let(:users) { FactoryBot.create_list(:external_user, 10) }
 
   def create_submissions
     10.times do
-      FactoryGirl.create(:submission, cause: 'submit', exercise: exercise, score: Forgery(:basic).number, user: users.sample)
+      FactoryBot.create(:submission, cause: 'submit', exercise: exercise, score: Forgery(:basic).number, user: users.sample)
     end
   end
 
   it 'validates the number of main files' do
-    exercise = FactoryGirl.create(:dummy)
-    exercise.files += FactoryGirl.create_pair(:file)
+    exercise = FactoryBot.create(:dummy)
+    exercise.files += FactoryBot.create_pair(:file)
     expect(exercise).to receive(:valid_main_file?).and_call_original
     exercise.save
     expect(exercise.errors[:files]).to be_present
@@ -46,7 +46,7 @@ describe Exercise do
   end
 
   describe '#average_percentage' do
-    let(:exercise) { FactoryGirl.create(:fibonacci) }
+    let(:exercise) { FactoryBot.create(:fibonacci) }
 
     context 'without submissions' do
       it 'returns nil' do
@@ -65,7 +65,7 @@ describe Exercise do
   end
 
   describe '#average_score' do
-    let(:exercise) { FactoryGirl.create(:fibonacci) }
+    let(:exercise) { FactoryBot.create(:fibonacci) }
 
     context 'without submissions' do
       it 'returns nil' do
@@ -84,7 +84,7 @@ describe Exercise do
   end
 
   describe '#duplicate' do
-    let(:exercise) { FactoryGirl.create(:fibonacci) }
+    let(:exercise) { FactoryBot.create(:fibonacci) }
     after(:each) { exercise.duplicate }
 
     it 'duplicates the exercise' do
diff --git a/spec/models/external_user_spec.rb b/spec/models/external_user_spec.rb
index a47f4aca..5d1d0aae 100644
--- a/spec/models/external_user_spec.rb
+++ b/spec/models/external_user_spec.rb
@@ -13,7 +13,7 @@ describe ExternalUser do
 
   describe '#admin?' do
     it 'is false' do
-      expect(FactoryGirl.build(:external_user).admin?).to be false
+      expect(FactoryBot.build(:external_user).admin?).to be false
     end
   end
 
@@ -31,7 +31,7 @@ describe ExternalUser do
 
   describe '#teacher?' do
     it 'is false' do
-      expect(FactoryGirl.build(:external_user).teacher?).to be false
+      expect(FactoryBot.build(:external_user).teacher?).to be false
     end
   end
 end
diff --git a/spec/models/internal_user_spec.rb b/spec/models/internal_user_spec.rb
index 9a41d7b6..25f7e172 100644
--- a/spec/models/internal_user_spec.rb
+++ b/spec/models/internal_user_spec.rb
@@ -9,12 +9,12 @@ describe InternalUser do
   end
 
   it 'validates the uniqueness of the email address' do
-    user.update(email: FactoryGirl.create(:admin).email)
+    user.update(email: FactoryBot.create(:admin).email)
     expect(user.errors[:email]).to be_present
   end
 
   context 'when not activated' do
-    let(:user) { FactoryGirl.create(:teacher) }
+    let(:user) { FactoryBot.create(:teacher) }
 
     before(:each) do
       user.send(:setup_activation)
@@ -33,7 +33,7 @@ describe InternalUser do
   end
 
   context 'with a pending password reset' do
-    let(:user) { FactoryGirl.create(:teacher) }
+    let(:user) { FactoryBot.create(:teacher) }
     before(:each) { user.deliver_reset_password_instructions! }
 
     it 'validates the confirmation of the password' do
@@ -48,7 +48,7 @@ describe InternalUser do
   end
 
   context 'when complete' do
-    let(:user) { FactoryGirl.create(:teacher, activation_state: 'active') }
+    let(:user) { FactoryBot.create(:teacher, activation_state: 'active') }
 
     it 'does not validate the confirmation of the password' do
       user.update(password: password, password_confirmation: '')
@@ -71,8 +71,8 @@ describe InternalUser do
 
   describe '#admin?' do
     it 'is only true for admins' do
-      expect(FactoryGirl.build(:admin).admin?).to be true
-      expect(FactoryGirl.build(:teacher).admin?).to be false
+      expect(FactoryBot.build(:admin).admin?).to be true
+      expect(FactoryBot.build(:teacher).admin?).to be false
     end
   end
 
@@ -90,8 +90,8 @@ describe InternalUser do
 
   describe '#teacher?' do
     it 'is only true for teachers' do
-      expect(FactoryGirl.build(:admin).teacher?).to be false
-      expect(FactoryGirl.build(:teacher).teacher?).to be true
+      expect(FactoryBot.build(:admin).teacher?).to be false
+      expect(FactoryBot.build(:teacher).teacher?).to be true
     end
   end
 end
diff --git a/spec/models/submission_spec.rb b/spec/models/submission_spec.rb
index 64f4e49e..50fcf285 100644
--- a/spec/models/submission_spec.rb
+++ b/spec/models/submission_spec.rb
@@ -1,7 +1,7 @@
 require 'rails_helper'
 
 describe Submission do
-  let(:submission) { FactoryGirl.create(:submission, exercise: FactoryGirl.create(:dummy)) }
+  let(:submission) { FactoryBot.create(:submission, exercise: FactoryBot.create(:dummy)) }
 
   it 'validates the presence of a cause' do
     expect(described_class.create.errors[:cause]).to be_present
@@ -17,7 +17,7 @@ describe Submission do
   end
 
   describe '#main_file' do
-    let(:submission) { FactoryGirl.create(:submission) }
+    let(:submission) { FactoryBot.create(:submission) }
 
     it "returns the submission's main file" do
       expect(submission.main_file).to be_a(CodeOcean::File)
@@ -27,7 +27,7 @@ describe Submission do
 
   describe '#normalized_score' do
     context 'with a score' do
-      let(:submission) { FactoryGirl.create(:submission) }
+      let(:submission) { FactoryBot.create(:submission) }
       before(:each) { submission.score = submission.exercise.maximum_score / 2 }
 
       it 'returns the score as a value between 0 and 1' do
@@ -46,7 +46,7 @@ describe Submission do
 
   describe '#percentage' do
     context 'with a score' do
-      let(:submission) { FactoryGirl.create(:submission) }
+      let(:submission) { FactoryBot.create(:submission) }
       before(:each) { submission.score = submission.exercise.maximum_score / 2 }
 
       it 'returns the score expressed as a percentage' do
@@ -65,11 +65,11 @@ describe Submission do
 
   describe '#siblings' do
     let(:siblings) { described_class.find_by(user: user).siblings }
-    let(:user) { FactoryGirl.create(:external_user) }
+    let(:user) { FactoryBot.create(:external_user) }
 
     before(:each) do
       10.times.each_with_index do |_, index|
-        FactoryGirl.create(:submission, exercise: submission.exercise, user: (index.even? ? user : FactoryGirl.create(:external_user)))
+        FactoryBot.create(:submission, exercise: submission.exercise, user: (index.even? ? user : FactoryBot.create(:external_user)))
       end
     end
 
@@ -85,4 +85,53 @@ describe Submission do
       expect(submission.to_s).to eq(described_class.model_name.human)
     end
   end
+
+  describe '#redirect_to_feedback?' do
+
+    context 'with no exercise feedback' do
+      let(:exercise) {FactoryBot.create(:dummy)}
+      let(:user) {FactoryBot.build(:external_user, id: (11 - exercise.created_at.to_i % 10) % 10)}
+      let(:submission) {FactoryBot.build(:submission, exercise: exercise, user: user)}
+
+      it 'sends 10% of users to feedback page' do
+        expect(submission.send(:redirect_to_feedback?)).to be_truthy
+      end
+
+      it 'does not redirect other users' do
+        9.times do |i|
+          submission = FactoryBot.build(:submission, exercise: exercise, user: FactoryBot.build(:external_user, id: (11 - exercise.created_at.to_i % 10) - i - 1))
+          expect(submission.send(:redirect_to_feedback?)).to be_falsey
+        end
+      end
+    end
+
+    context 'with little exercise feedback' do
+      let(:exercise) {FactoryBot.create(:dummy_with_user_feedbacks)}
+      let(:user) {FactoryBot.build(:external_user, id: (11 - exercise.created_at.to_i % 10) % 10)}
+      let(:submission) {FactoryBot.build(:submission, exercise: exercise, user: user)}
+
+      it 'sends 10% of users to feedback page' do
+        expect(submission.send(:redirect_to_feedback?)).to be_truthy
+      end
+
+      it 'does not redirect other users' do
+        9.times do |i|
+          submission = FactoryBot.build(:submission, exercise: exercise, user: FactoryBot.build(:external_user, id: (11 - exercise.created_at.to_i % 10) - i - 1))
+          expect(submission.send(:redirect_to_feedback?)).to be_falsey
+        end
+      end
+    end
+
+    context 'with enough exercise feedback' do
+      let(:exercise) {FactoryBot.create(:dummy_with_user_feedbacks, user_feedbacks_count: 42)}
+      let(:user) {FactoryBot.create(:external_user)}
+
+      it 'sends nobody to feedback page' do
+        30.times do |i|
+          submission = FactoryBot.create(:submission, exercise: exercise, user: FactoryBot.create(:external_user))
+          expect(submission.send(:redirect_to_feedback?)).to be_falsey
+        end
+      end
+    end
+  end
 end
diff --git a/spec/policies/admin/dashboard_policy_spec.rb b/spec/policies/admin/dashboard_policy_spec.rb
index 0592843a..71a7adcd 100644
--- a/spec/policies/admin/dashboard_policy_spec.rb
+++ b/spec/policies/admin/dashboard_policy_spec.rb
@@ -5,15 +5,15 @@ describe Admin::DashboardPolicy do
 
   permissions :show? do
     it 'grants access to admins' do
-      expect(subject).to permit(FactoryGirl.build(:admin), :dashboard)
+      expect(subject).to permit(FactoryBot.build(:admin), :dashboard)
     end
 
     it 'does not grant access to teachers' do
-      expect(subject).not_to permit(FactoryGirl.build(:teacher), :dashboard)
+      expect(subject).not_to permit(FactoryBot.build(:teacher), :dashboard)
     end
 
     it 'does not grant access to external users' do
-      expect(subject).not_to permit(FactoryGirl.build(:external_user), :dashboard)
+      expect(subject).not_to permit(FactoryBot.build(:external_user), :dashboard)
     end
   end
 end
diff --git a/spec/policies/code_ocean/file_policy_spec.rb b/spec/policies/code_ocean/file_policy_spec.rb
index a41f0a0b..ac928cb3 100644
--- a/spec/policies/code_ocean/file_policy_spec.rb
+++ b/spec/policies/code_ocean/file_policy_spec.rb
@@ -3,15 +3,15 @@ require 'rails_helper'
 describe CodeOcean::FilePolicy do
   subject { described_class }
 
-  let(:exercise) { FactoryGirl.create(:fibonacci) }
-  let(:submission) { FactoryGirl.create(:submission) }
+  let(:exercise) { FactoryBot.create(:fibonacci) }
+  let(:submission) { FactoryBot.create(:submission) }
 
   permissions :create? do
     context 'as part of an exercise' do
       let(:file) { exercise.files.first }
 
       it 'grants access to admins' do
-        expect(subject).to permit(FactoryGirl.build(:admin), file)
+        expect(subject).to permit(FactoryBot.build(:admin), file)
       end
 
       it 'grants access to authors' do
@@ -20,7 +20,7 @@ describe CodeOcean::FilePolicy do
 
       it 'does not grant access to all other users' do
         [:external_user, :teacher].each do |factory_name|
-          expect(subject).not_to permit(FactoryGirl.build(factory_name), file)
+          expect(subject).not_to permit(FactoryBot.build(factory_name), file)
         end
       end
     end
@@ -34,7 +34,7 @@ describe CodeOcean::FilePolicy do
 
       it 'does not grant access to all other users' do
         [:admin, :external_user, :teacher].each do |factory_name|
-          expect(subject).not_to permit(FactoryGirl.build(factory_name), file)
+          expect(subject).not_to permit(FactoryBot.build(factory_name), file)
         end
       end
     end
@@ -45,7 +45,7 @@ describe CodeOcean::FilePolicy do
       let(:file) { exercise.files.first }
 
       it 'grants access to admins' do
-        expect(subject).to permit(FactoryGirl.build(:admin), file)
+        expect(subject).to permit(FactoryBot.build(:admin), file)
       end
 
       it 'grants access to authors' do
@@ -54,7 +54,7 @@ describe CodeOcean::FilePolicy do
 
       it 'does not grant access to all other users' do
         [:external_user, :teacher].each do |factory_name|
-          expect(subject).not_to permit(FactoryGirl.build(factory_name), file)
+          expect(subject).not_to permit(FactoryBot.build(factory_name), file)
         end
       end
     end
@@ -64,7 +64,7 @@ describe CodeOcean::FilePolicy do
 
       it 'does not grant access to anyone' do
         [:admin, :external_user, :teacher].each do |factory_name|
-          expect(subject).not_to permit(FactoryGirl.build(factory_name), file)
+          expect(subject).not_to permit(FactoryBot.build(factory_name), file)
         end
       end
     end
diff --git a/spec/policies/consumer_policy_spec.rb b/spec/policies/consumer_policy_spec.rb
index 01b74dd3..36f96288 100644
--- a/spec/policies/consumer_policy_spec.rb
+++ b/spec/policies/consumer_policy_spec.rb
@@ -6,9 +6,9 @@ describe ConsumerPolicy do
   [:create?, :destroy?, :edit?, :index?, :new?, :show?, :update?].each do |action|
     permissions(action) do
       it 'grants access to admins only' do
-        expect(subject).to permit(FactoryGirl.build(:admin), Consumer.new)
+        expect(subject).to permit(FactoryBot.build(:admin), Consumer.new)
         [:external_user, :teacher].each do |factory_name|
-          expect(subject).not_to permit(FactoryGirl.build(factory_name), Consumer.new)
+          expect(subject).not_to permit(FactoryBot.build(factory_name), Consumer.new)
         end
       end
     end
diff --git a/spec/policies/error_policy_spec.rb b/spec/policies/error_policy_spec.rb
index 185eeeae..2fff2e7e 100644
--- a/spec/policies/error_policy_spec.rb
+++ b/spec/policies/error_policy_spec.rb
@@ -3,20 +3,20 @@ require 'rails_helper'
 describe ErrorPolicy do
   subject { described_class }
 
-  let(:error) { FactoryGirl.build(:error) }
+  let(:error) { FactoryBot.build(:error) }
 
   [:create?, :index?, :new?].each do |action|
     permissions(action) do
       it 'grants access to admins' do
-        expect(subject).to permit(FactoryGirl.build(:admin), error)
+        expect(subject).to permit(FactoryBot.build(:admin), error)
       end
 
       it 'grants access to teachers' do
-        expect(subject).to permit(FactoryGirl.build(:teacher), error)
+        expect(subject).to permit(FactoryBot.build(:teacher), error)
       end
 
       it 'does not grant access to external users' do
-        expect(subject).not_to permit(FactoryGirl.build(:external_user), error)
+        expect(subject).not_to permit(FactoryBot.build(:external_user), error)
       end
     end
   end
@@ -24,7 +24,7 @@ describe ErrorPolicy do
   [:destroy?, :edit?, :show?, :update?].each do |action|
     permissions(action) do
       it 'grants access to admins' do
-        expect(subject).to permit(FactoryGirl.build(:admin), error)
+        expect(subject).to permit(FactoryBot.build(:admin), error)
       end
 
       it 'grants access to authors' do
@@ -33,7 +33,7 @@ describe ErrorPolicy do
 
       it 'does not grant access to all other users' do
         [:external_user, :teacher].each do |factory_name|
-          expect(subject).not_to permit(FactoryGirl.build(factory_name), error)
+          expect(subject).not_to permit(FactoryBot.build(factory_name), error)
         end
       end
     end
diff --git a/spec/policies/execution_environment_policy_spec.rb b/spec/policies/execution_environment_policy_spec.rb
index 6f41f7e4..ef5787b9 100644
--- a/spec/policies/execution_environment_policy_spec.rb
+++ b/spec/policies/execution_environment_policy_spec.rb
@@ -3,20 +3,20 @@ require 'rails_helper'
 describe ExecutionEnvironmentPolicy do
   subject { described_class }
 
-  let(:execution_environment) { FactoryGirl.build(:ruby) }
+  let(:execution_environment) { FactoryBot.build(:ruby) }
 
   [:create?, :index?, :new?].each do |action|
     permissions(action) do
       it 'grants access to admins' do
-        expect(subject).to permit(FactoryGirl.build(:admin), execution_environment)
+        expect(subject).to permit(FactoryBot.build(:admin), execution_environment)
       end
 
       it 'grants access to teachers' do
-        expect(subject).to permit(FactoryGirl.build(:teacher), execution_environment)
+        expect(subject).to permit(FactoryBot.build(:teacher), execution_environment)
       end
 
       it 'does not grant access to external users' do
-        expect(subject).not_to permit(FactoryGirl.build(:external_user), execution_environment)
+        expect(subject).not_to permit(FactoryBot.build(:external_user), execution_environment)
       end
     end
   end
@@ -24,7 +24,7 @@ describe ExecutionEnvironmentPolicy do
   [:execute_command?, :shell?, :statistics?].each do |action|
     permissions(action) do
       it 'grants access to admins' do
-        expect(subject).to permit(FactoryGirl.build(:admin), execution_environment)
+        expect(subject).to permit(FactoryBot.build(:admin), execution_environment)
       end
 
       it 'grants access to authors' do
@@ -33,7 +33,7 @@ describe ExecutionEnvironmentPolicy do
 
       it 'does not grant access to all other users' do
         [:external_user, :teacher].each do |factory_name|
-          expect(subject).not_to permit(FactoryGirl.build(factory_name), execution_environment)
+          expect(subject).not_to permit(FactoryBot.build(factory_name), execution_environment)
         end
       end
     end
@@ -42,7 +42,7 @@ describe ExecutionEnvironmentPolicy do
   [:destroy?, :edit?, :show?, :update?].each do |action|
     permissions(action) do
       it 'grants access to admins' do
-        expect(subject).to permit(FactoryGirl.build(:admin), execution_environment)
+        expect(subject).to permit(FactoryBot.build(:admin), execution_environment)
       end
 
       it 'does not grant access to authors' do
@@ -51,7 +51,7 @@ describe ExecutionEnvironmentPolicy do
 
       it 'does not grant access to all other users' do
         [:external_user, :teacher].each do |factory_name|
-          expect(subject).not_to permit(FactoryGirl.build(factory_name), execution_environment)
+          expect(subject).not_to permit(FactoryBot.build(factory_name), execution_environment)
         end
       end
     end
diff --git a/spec/policies/exercise_policy_spec.rb b/spec/policies/exercise_policy_spec.rb
index 2799123f..f0024fa8 100644
--- a/spec/policies/exercise_policy_spec.rb
+++ b/spec/policies/exercise_policy_spec.rb
@@ -3,13 +3,13 @@ require 'rails_helper'
 describe ExercisePolicy do
   subject { described_class }
 
-let(:exercise) { FactoryGirl.build(:dummy) }
+let(:exercise) { FactoryBot.build(:dummy) }
   
   permissions :batch_update? do
     it 'grants access to admins only' do
-      expect(subject).to permit(FactoryGirl.build(:admin), exercise)
+      expect(subject).to permit(FactoryBot.build(:admin), exercise)
       [:external_user, :teacher].each do |factory_name|
-        expect(subject).not_to permit(FactoryGirl.build(factory_name), exercise)
+        expect(subject).not_to permit(FactoryBot.build(factory_name), exercise)
       end
     end
   end
@@ -17,15 +17,15 @@ let(:exercise) { FactoryGirl.build(:dummy) }
   [:create?, :index?, :new?].each do |action|
     permissions(action) do
       it 'grants access to admins' do
-        expect(subject).to permit(FactoryGirl.build(:admin), exercise)
+        expect(subject).to permit(FactoryBot.build(:admin), exercise)
       end
 
       it 'grants access to teachers' do
-        expect(subject).to permit(FactoryGirl.build(:teacher), exercise)
+        expect(subject).to permit(FactoryBot.build(:teacher), exercise)
       end
 
       it 'does not grant access to external users' do
-        expect(subject).not_to permit(FactoryGirl.build(:external_user), exercise)
+        expect(subject).not_to permit(FactoryBot.build(:external_user), exercise)
       end
     end
   end
@@ -33,7 +33,7 @@ let(:exercise) { FactoryGirl.build(:dummy) }
   [:clone?, :destroy?, :edit?, :statistics?, :update?].each do |action|
     permissions(action) do
       it 'grants access to admins' do
-        expect(subject).to permit(FactoryGirl.build(:admin), exercise)
+        expect(subject).to permit(FactoryBot.build(:admin), exercise)
       end
 
       it 'grants access to authors' do
@@ -42,7 +42,7 @@ let(:exercise) { FactoryGirl.build(:dummy) }
 
       it 'does not grant access to all other users' do
         [:external_user, :teacher].each do |factory_name|
-          expect(subject).not_to permit(FactoryGirl.build(factory_name), exercise)
+          expect(subject).not_to permit(FactoryBot.build(factory_name), exercise)
         end
       end
     end
@@ -51,7 +51,7 @@ let(:exercise) { FactoryGirl.build(:dummy) }
   [:show?].each do |action|
     permissions(action) do
       it 'not grants access to external users' do
-        expect(subject).not_to permit(FactoryGirl.build(:external_user), exercise)
+        expect(subject).not_to permit(FactoryBot.build(:external_user), exercise)
       end
     end
   end
@@ -60,7 +60,7 @@ let(:exercise) { FactoryGirl.build(:dummy) }
     permissions(action) do
       it 'grants access to anyone' do
         [:admin, :external_user, :teacher].each do |factory_name|
-          expect(subject).to permit(FactoryGirl.build(factory_name), Exercise.new)
+          expect(subject).to permit(FactoryBot.build(factory_name), Exercise.new)
         end
       end
     end
@@ -69,13 +69,13 @@ let(:exercise) { FactoryGirl.build(:dummy) }
   describe ExercisePolicy::Scope do
     describe '#resolve' do
       before(:all) do
-        @admin = FactoryGirl.create(:admin)
-        @external_user = FactoryGirl.create(:external_user)
-        @teacher = FactoryGirl.create(:teacher)
+        @admin = FactoryBot.create(:admin)
+        @external_user = FactoryBot.create(:external_user)
+        @teacher = FactoryBot.create(:teacher)
 
         [@admin, @teacher].each do |user|
           [true, false].each do |public|
-            FactoryGirl.create(:dummy, public: public, user_id: user.id, user_type: InternalUser.class.name)
+            FactoryBot.create(:dummy, public: public, user_id: user.id, user_type: InternalUser.class.name)
           end
         end
       end
diff --git a/spec/policies/external_user_policy_spec.rb b/spec/policies/external_user_policy_spec.rb
index be506c7f..d668c305 100644
--- a/spec/policies/external_user_policy_spec.rb
+++ b/spec/policies/external_user_policy_spec.rb
@@ -6,9 +6,9 @@ describe ExternalUserPolicy do
   [:create?, :destroy?, :edit?, :index?, :new?, :show?, :update?].each do |action|
     permissions(action) do
       it 'grants access to admins only' do
-        expect(subject).to permit(FactoryGirl.build(:admin), ExternalUser.new)
+        expect(subject).to permit(FactoryBot.build(:admin), ExternalUser.new)
         [:external_user, :teacher].each do |factory_name|
-          expect(subject).not_to permit(FactoryGirl.build(factory_name), ExternalUser.new)
+          expect(subject).not_to permit(FactoryBot.build(factory_name), ExternalUser.new)
         end
       end
     end
diff --git a/spec/policies/file_type_policy_spec.rb b/spec/policies/file_type_policy_spec.rb
index 042e4393..55ec4120 100644
--- a/spec/policies/file_type_policy_spec.rb
+++ b/spec/policies/file_type_policy_spec.rb
@@ -3,20 +3,20 @@ require 'rails_helper'
 describe FileTypePolicy do
   subject { described_class }
 
-  let(:file_type) { FactoryGirl.build(:dot_rb) }
+  let(:file_type) { FactoryBot.build(:dot_rb) }
 
   [:create?, :index?, :new?].each do |action|
     permissions(action) do
       it 'grants access to admins' do
-        expect(subject).to permit(FactoryGirl.build(:admin), file_type)
+        expect(subject).to permit(FactoryBot.build(:admin), file_type)
       end
 
       it 'grants access to teachers' do
-        expect(subject).to permit(FactoryGirl.build(:teacher), file_type)
+        expect(subject).to permit(FactoryBot.build(:teacher), file_type)
       end
 
       it 'does not grant access to external users' do
-        expect(subject).not_to permit(FactoryGirl.build(:external_user), file_type)
+        expect(subject).not_to permit(FactoryBot.build(:external_user), file_type)
       end
     end
   end
@@ -24,7 +24,7 @@ describe FileTypePolicy do
   [:destroy?, :edit?, :show?, :update?].each do |action|
     permissions(action) do
       it 'grants access to admins' do
-        expect(subject).to permit(FactoryGirl.build(:admin), file_type)
+        expect(subject).to permit(FactoryBot.build(:admin), file_type)
       end
 
       it 'grants access to authors' do
@@ -33,7 +33,7 @@ describe FileTypePolicy do
 
       it 'does not grant access to all other users' do
         [:external_user, :teacher].each do |factory_name|
-          expect(subject).not_to permit(FactoryGirl.build(factory_name), file_type)
+          expect(subject).not_to permit(FactoryBot.build(factory_name), file_type)
         end
       end
     end
diff --git a/spec/policies/hint_policy_spec.rb b/spec/policies/hint_policy_spec.rb
index ccde798f..2aa9d9e5 100644
--- a/spec/policies/hint_policy_spec.rb
+++ b/spec/policies/hint_policy_spec.rb
@@ -3,20 +3,20 @@ require 'rails_helper'
 describe HintPolicy do
   subject { described_class }
 
-  let(:hint) { FactoryGirl.build(:ruby_no_method_error) }
+  let(:hint) { FactoryBot.build(:ruby_no_method_error) }
 
   [:create?, :index?, :new?].each do |action|
     permissions(action) do
       it 'grants access to admins' do
-        expect(subject).to permit(FactoryGirl.build(:admin), hint)
+        expect(subject).to permit(FactoryBot.build(:admin), hint)
       end
 
       it 'grants access to teachers' do
-        expect(subject).to permit(FactoryGirl.build(:teacher), hint)
+        expect(subject).to permit(FactoryBot.build(:teacher), hint)
       end
 
       it 'does not grant access to external users' do
-        expect(subject).not_to permit(FactoryGirl.build(:external_user), hint)
+        expect(subject).not_to permit(FactoryBot.build(:external_user), hint)
       end
     end
   end
@@ -24,7 +24,7 @@ describe HintPolicy do
   [:destroy?, :edit?, :show?, :update?].each do |action|
     permissions(action) do
       it 'grants access to admins' do
-        expect(subject).to permit(FactoryGirl.build(:admin), hint)
+        expect(subject).to permit(FactoryBot.build(:admin), hint)
       end
 
       it 'grants access to authors' do
@@ -33,7 +33,7 @@ describe HintPolicy do
 
       it 'does not grant access to all other users' do
         [:external_user, :teacher].each do |factory_name|
-          expect(subject).not_to permit(FactoryGirl.build(factory_name), hint)
+          expect(subject).not_to permit(FactoryBot.build(factory_name), hint)
         end
       end
     end
diff --git a/spec/policies/internal_user_policy_spec.rb b/spec/policies/internal_user_policy_spec.rb
index 3ad6e7d9..0644e358 100644
--- a/spec/policies/internal_user_policy_spec.rb
+++ b/spec/policies/internal_user_policy_spec.rb
@@ -6,9 +6,9 @@ describe InternalUserPolicy do
   [:create?, :edit?, :index?, :new?, :show?, :update?].each do |action|
     permissions(action) do
       it 'grants access to admins only' do
-        expect(subject).to permit(FactoryGirl.build(:admin), InternalUser.new)
+        expect(subject).to permit(FactoryBot.build(:admin), InternalUser.new)
         [:external_user, :teacher].each do |factory_name|
-          expect(subject).not_to permit(FactoryGirl.build(factory_name), InternalUser.new)
+          expect(subject).not_to permit(FactoryBot.build(factory_name), InternalUser.new)
         end
       end
     end
@@ -18,16 +18,16 @@ describe InternalUserPolicy do
     context 'with an admin user' do
       it 'grants access to no one' do
         [:admin, :external_user, :teacher].each do |factory_name|
-          expect(subject).not_to permit(FactoryGirl.build(factory_name), FactoryGirl.build(:admin))
+          expect(subject).not_to permit(FactoryBot.build(factory_name), FactoryBot.build(:admin))
         end
       end
     end
 
     context 'with a non-admin user' do
       it 'grants access to admins only' do
-        expect(subject).to permit(FactoryGirl.build(:admin), InternalUser.new)
+        expect(subject).to permit(FactoryBot.build(:admin), InternalUser.new)
         [:external_user, :teacher].each do |factory_name|
-          expect(subject).not_to permit(FactoryGirl.build(factory_name), FactoryGirl.build(:teacher))
+          expect(subject).not_to permit(FactoryBot.build(factory_name), FactoryBot.build(:teacher))
         end
       end
     end
diff --git a/spec/policies/submission_policy_spec.rb b/spec/policies/submission_policy_spec.rb
index f844b984..9d79b4e1 100644
--- a/spec/policies/submission_policy_spec.rb
+++ b/spec/policies/submission_policy_spec.rb
@@ -6,7 +6,7 @@ describe SubmissionPolicy do
   permissions :create? do
     it 'grants access to anyone' do
       [:admin, :external_user, :teacher].each do |factory_name|
-        expect(subject).to permit(FactoryGirl.build(factory_name), Submission.new)
+        expect(subject).to permit(FactoryBot.build(factory_name), Submission.new)
       end
     end
   end
@@ -14,21 +14,21 @@ describe SubmissionPolicy do
   [:download_file?, :render_file?, :run?, :score?, :show?, :statistics?, :stop?, :test?].each do |action|
     permissions(action) do
       it 'grants access to admins' do
-        expect(subject).to permit(FactoryGirl.build(:admin), Submission.new)
+        expect(subject).to permit(FactoryBot.build(:admin), Submission.new)
       end
 
       it 'grants access to authors' do
-        user = FactoryGirl.create(:external_user)
-        expect(subject).to permit(user, FactoryGirl.build(:submission, exercise: Exercise.new, user_id: user.id, user_type: user.class.name))
+        user = FactoryBot.create(:external_user)
+        expect(subject).to permit(user, FactoryBot.build(:submission, exercise: Exercise.new, user_id: user.id, user_type: user.class.name))
       end
     end
   end
 
   permissions :index? do
     it 'grants access to admins only' do
-      expect(subject).to permit(FactoryGirl.build(:admin), Submission.new)
+      expect(subject).to permit(FactoryBot.build(:admin), Submission.new)
       [:external_user, :teacher].each do |factory_name|
-        expect(subject).not_to permit(FactoryGirl.build(factory_name), Submission.new)
+        expect(subject).not_to permit(FactoryBot.build(factory_name), Submission.new)
       end
     end
   end
diff --git a/spec/support/docker.rb b/spec/support/docker.rb
index 7cb16ed4..e2be05f9 100644
--- a/spec/support/docker.rb
+++ b/spec/support/docker.rb
@@ -1,5 +1,5 @@
 CONTAINER = Docker::Container.send(:new, Docker::Connection.new('http://example.org', {}), 'id' => SecureRandom.hex)
-IMAGE = Docker::Image.new(Docker::Connection.new('http://example.org', {}), 'id' => SecureRandom.hex, 'RepoTags' => [FactoryGirl.attributes_for(:ruby)[:docker_image]])
+IMAGE = Docker::Image.new(Docker::Connection.new('http://example.org', {}), 'id' => SecureRandom.hex, 'RepoTags' => [FactoryBot.attributes_for(:ruby)[:docker_image]])
 
 RSpec.configure do |config|
   config.before(:each) do |example|
diff --git a/spec/uploaders/file_uploader_spec.rb b/spec/uploaders/file_uploader_spec.rb
index eabc37d1..3d335fa4 100644
--- a/spec/uploaders/file_uploader_spec.rb
+++ b/spec/uploaders/file_uploader_spec.rb
@@ -2,7 +2,7 @@ require 'rails_helper'
 
 describe FileUploader do
   let(:file_path) { Rails.root.join('db', 'seeds', 'fibonacci', 'exercise.rb') }
-  let(:uploader) { described_class.new(FactoryGirl.create(:file)) }
+  let(:uploader) { described_class.new(FactoryBot.create(:file)) }
 
   before(:each) { uploader.store!(File.open(file_path, 'r')) }
   after(:each) { uploader.remove! }
diff --git a/spec/views/execution_environments/shell.html.slim_spec.rb b/spec/views/execution_environments/shell.html.slim_spec.rb
index 791804e3..84adb038 100644
--- a/spec/views/execution_environments/shell.html.slim_spec.rb
+++ b/spec/views/execution_environments/shell.html.slim_spec.rb
@@ -1,7 +1,7 @@
 require 'rails_helper'
 
 describe 'execution_environments/shell.html.slim' do
-  let(:execution_environment) { FactoryGirl.create(:ruby) }
+  let(:execution_environment) { FactoryBot.create(:ruby) }
 
   before(:each) do
     assign(:execution_environment, execution_environment)
diff --git a/spec/views/exercises/implement.html.slim_spec.rb b/spec/views/exercises/implement.html.slim_spec.rb
index 84a65fa2..7c5e641a 100644
--- a/spec/views/exercises/implement.html.slim_spec.rb
+++ b/spec/views/exercises/implement.html.slim_spec.rb
@@ -1,12 +1,12 @@
 require 'rails_helper'
 
 describe 'exercises/implement.html.slim' do
-  let(:exercise) { FactoryGirl.create(:fibonacci) }
+  let(:exercise) { FactoryBot.create(:fibonacci) }
   let(:files) { exercise.files.visible }
   let(:non_binary_files) { files.reject { |file| file.file_type.binary? } }
 
   before(:each) do
-    assign(:current_user, FactoryGirl.create(:admin))
+    assign(:current_user, FactoryBot.create(:admin))
     assign(:exercise, exercise)
     assign(:files, files)
     assign(:paths, [])
diff --git a/test/factories/error_template_attributes.rb b/test/factories/error_template_attributes.rb
index 24adb856..84e65757 100644
--- a/test/factories/error_template_attributes.rb
+++ b/test/factories/error_template_attributes.rb
@@ -1,4 +1,4 @@
-FactoryGirl.define do
+FactoryBot.define do
   factory :error_template_attribute do
     error_template nil
     key "MyString"
diff --git a/test/factories/error_templates.rb b/test/factories/error_templates.rb
index 2abf68c9..3a2637ca 100644
--- a/test/factories/error_templates.rb
+++ b/test/factories/error_templates.rb
@@ -1,4 +1,4 @@
-FactoryGirl.define do
+FactoryBot.define do
   factory :error_template do
     execution_environment nil
     name "MyString"
diff --git a/test/factories/structured_error_attributes.rb b/test/factories/structured_error_attributes.rb
index 7485967c..0b720b23 100644
--- a/test/factories/structured_error_attributes.rb
+++ b/test/factories/structured_error_attributes.rb
@@ -1,4 +1,4 @@
-FactoryGirl.define do
+FactoryBot.define do
   factory :structured_error_attribute do
     structured_error nil
     error_template_attribute nil
diff --git a/test/factories/structured_errors.rb b/test/factories/structured_errors.rb
index 4a87cec1..041b4bbd 100644
--- a/test/factories/structured_errors.rb
+++ b/test/factories/structured_errors.rb
@@ -1,4 +1,4 @@
-FactoryGirl.define do
+FactoryBot.define do
   factory :structured_error do
     error_template nil
     file nil