diff --git a/cmd/poseidon/main.go b/cmd/poseidon/main.go
index b0da270..9281c49 100644
--- a/cmd/poseidon/main.go
+++ b/cmd/poseidon/main.go
@@ -57,25 +57,43 @@ func runServer(server *http.Server) {
 	}
 }
 
-func initServer() *http.Server {
+func createNomadManager() (runnerManager runner.Manager, environmentManager environment.ManagerHandler) {
 	// API initialization
 	nomadAPIClient, err := nomad.NewExecutorAPI(&config.Config.Nomad)
 	if err != nil {
 		log.WithError(err).WithField("nomad config", config.Config.Nomad).Fatal("Error creating Nomad API client")
 	}
 
-	runnerManager := runner.NewNomadRunnerManager(nomadAPIClient, context.Background())
-	environmentManager, err := environment.
+	runnerManager = runner.NewNomadRunnerManager(nomadAPIClient, context.Background())
+	environmentManager, err = environment.
 		NewNomadEnvironmentManager(runnerManager, nomadAPIClient, config.Config.Server.TemplateJobFile)
 	if err != nil {
 		log.WithError(err).Fatal("Error initializing environment manager")
 	}
+	return runnerManager, environmentManager
+}
+
+func createAWSManager(nextRunnerManager runner.Manager, nextEnvironmentManager environment.ManagerHandler) (
+	runnerManager runner.Manager, environmentManager environment.ManagerHandler) {
+	runnerManager = runner.NewAWSRunnerManager()
+	runnerManager.SetNextHandler(nextRunnerManager)
+
+	environmentManager = environment.NewAWSEnvironmentManager(runnerManager)
+	environmentManager.SetNextHandler(nextEnvironmentManager)
+
+	return runnerManager, environmentManager
+}
+
+// initServer builds the http server and configures it with the chain of responsibility for multiple managers.
+func initServer() *http.Server {
+	nomadRunnerManager, nomadEnvironmentManager := createNomadManager()
+	awsRunnerManager, awsEnvironmentManager := createAWSManager(nomadRunnerManager, nomadEnvironmentManager)
 
 	return &http.Server{
 		Addr:        config.Config.Server.URL().Host,
 		ReadTimeout: time.Second * 15,
 		IdleTimeout: time.Second * 60,
-		Handler:     api.NewRouter(runnerManager, environmentManager),
+		Handler:     api.NewRouter(awsRunnerManager, awsEnvironmentManager),
 	}
 }
 
diff --git a/internal/api/api.go b/internal/api/api.go
index 9339b28..0d61011 100644
--- a/internal/api/api.go
+++ b/internal/api/api.go
@@ -27,7 +27,7 @@ const (
 // always returns a router for the newest version of our API. We
 // use gorilla/mux because it is more convenient than net/http, e.g.
 // when extracting path parameters.
-func NewRouter(runnerManager runner.Manager, environmentManager environment.Manager) *mux.Router {
+func NewRouter(runnerManager runner.Manager, environmentManager environment.ManagerHandler) *mux.Router {
 	router := mux.NewRouter()
 	// this can later be restricted to a specific host with
 	// `router.Host(...)` and to HTTPS with `router.Schemes("https")`
@@ -37,7 +37,8 @@ func NewRouter(runnerManager runner.Manager, environmentManager environment.Mana
 }
 
 // configureV1Router configures a given router with the routes of version 1 of the Poseidon API.
-func configureV1Router(router *mux.Router, runnerManager runner.Manager, environmentManager environment.Manager) {
+func configureV1Router(router *mux.Router,
+	runnerManager runner.Manager, environmentManager environment.ManagerHandler) {
 	router.NotFoundHandler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		log.WithField("request", r).Debug("Not Found Handler")
 		w.WriteHeader(http.StatusNotFound)
diff --git a/internal/api/environments.go b/internal/api/environments.go
index 14bce65..11ec34f 100644
--- a/internal/api/environments.go
+++ b/internal/api/environments.go
@@ -24,7 +24,7 @@ const (
 var ErrMissingURLParameter = errors.New("url parameter missing")
 
 type EnvironmentController struct {
-	manager environment.Manager
+	manager environment.ManagerHandler
 }
 
 type ExecutionEnvironmentsResponse struct {
diff --git a/internal/api/environments_test.go b/internal/api/environments_test.go
index 2947744..03e83c0 100644
--- a/internal/api/environments_test.go
+++ b/internal/api/environments_test.go
@@ -21,7 +21,7 @@ import (
 
 type EnvironmentControllerTestSuite struct {
 	suite.Suite
-	manager *environment.ManagerMock
+	manager *environment.ManagerHandlerMock
 	router  *mux.Router
 }
 
@@ -30,7 +30,7 @@ func TestEnvironmentControllerTestSuite(t *testing.T) {
 }
 
 func (s *EnvironmentControllerTestSuite) SetupTest() {
-	s.manager = &environment.ManagerMock{}
+	s.manager = &environment.ManagerHandlerMock{}
 	s.router = NewRouter(nil, s.manager)
 }
 
diff --git a/internal/api/runners.go b/internal/api/runners.go
index ca411e6..888d5ea 100644
--- a/internal/api/runners.go
+++ b/internal/api/runners.go
@@ -24,7 +24,7 @@ const (
 )
 
 type RunnerController struct {
-	manager      runner.Manager
+	manager      runner.Accessor
 	runnerRouter *mux.Router
 }
 
@@ -52,10 +52,10 @@ func (r *RunnerController) provide(writer http.ResponseWriter, request *http.Req
 	environmentID := dto.EnvironmentID(runnerRequest.ExecutionEnvironmentID)
 	nextRunner, err := r.manager.Claim(environmentID, runnerRequest.InactivityTimeout)
 	if err != nil {
-		switch err {
-		case runner.ErrUnknownExecutionEnvironment:
+		switch {
+		case errors.Is(err, runner.ErrUnknownExecutionEnvironment):
 			writeNotFound(writer, err)
-		case runner.ErrNoRunnersAvailable:
+		case errors.Is(err, runner.ErrNoRunnersAvailable):
 			log.WithField("environment", environmentID).Warn("No runners available")
 			writeInternalServerError(writer, err, dto.ErrorNomadOverload)
 		default:
diff --git a/internal/environment/abstract_manager.go b/internal/environment/abstract_manager.go
new file mode 100644
index 0000000..38788b6
--- /dev/null
+++ b/internal/environment/abstract_manager.go
@@ -0,0 +1,40 @@
+package environment
+
+import (
+	"github.com/openHPI/poseidon/internal/runner"
+	"github.com/openHPI/poseidon/pkg/dto"
+)
+
+// AbstractManager is used to have a fallback environment manager in the chain of responsibility
+// following the null object pattern.
+type AbstractManager struct {
+	nextHandler ManagerHandler
+}
+
+func (n *AbstractManager) SetNextHandler(next ManagerHandler) {
+	n.nextHandler = next
+}
+
+func (n *AbstractManager) NextHandler() ManagerHandler {
+	return n.nextHandler
+}
+
+func (n *AbstractManager) List(_ bool) ([]runner.ExecutionEnvironment, error) {
+	return []runner.ExecutionEnvironment{}, nil
+}
+
+func (n *AbstractManager) Get(_ dto.EnvironmentID, _ bool) (runner.ExecutionEnvironment, error) {
+	return nil, runner.ErrNullObject
+}
+
+func (n *AbstractManager) CreateOrUpdate(_ dto.EnvironmentID, _ dto.ExecutionEnvironmentRequest) (bool, error) {
+	return false, nil
+}
+
+func (n *AbstractManager) Delete(_ dto.EnvironmentID) (bool, error) {
+	return false, nil
+}
+
+func (n *AbstractManager) Statistics() map[dto.EnvironmentID]*dto.StatisticalExecutionEnvironmentData {
+	return map[dto.EnvironmentID]*dto.StatisticalExecutionEnvironmentData{}
+}
diff --git a/internal/environment/aws_manager.go b/internal/environment/aws_manager.go
new file mode 100644
index 0000000..edb2a53
--- /dev/null
+++ b/internal/environment/aws_manager.go
@@ -0,0 +1,57 @@
+package environment
+
+import (
+	"fmt"
+	"github.com/openHPI/poseidon/internal/runner"
+	"github.com/openHPI/poseidon/pkg/dto"
+)
+
+// AWSEnvironmentManager contains no functionality at the moment.
+// IMPROVE: Create Lambda functions dynamically.
+type AWSEnvironmentManager struct {
+	*AbstractManager
+	runnerManager runner.Accessor
+}
+
+func NewAWSEnvironmentManager(runnerManager runner.Accessor) *AWSEnvironmentManager {
+	m := &AWSEnvironmentManager{&AbstractManager{nil}, runnerManager}
+	runnerManager.Load()
+	return m
+}
+
+func (a *AWSEnvironmentManager) List(fetch bool) ([]runner.ExecutionEnvironment, error) {
+	list, err := a.NextHandler().List(fetch)
+	if err != nil {
+		return nil, fmt.Errorf("aws wraped: %w", err)
+	}
+	return list, nil
+}
+
+func (a *AWSEnvironmentManager) Get(id dto.EnvironmentID, fetch bool) (runner.ExecutionEnvironment, error) {
+	e, err := a.NextHandler().Get(id, fetch)
+	if err != nil {
+		return nil, fmt.Errorf("aws wraped: %w", err)
+	}
+	return e, nil
+}
+
+func (a *AWSEnvironmentManager) CreateOrUpdate(
+	id dto.EnvironmentID, request dto.ExecutionEnvironmentRequest) (bool, error) {
+	isCreated, err := a.NextHandler().CreateOrUpdate(id, request)
+	if err != nil {
+		return false, fmt.Errorf("aws wraped: %w", err)
+	}
+	return isCreated, nil
+}
+
+func (a *AWSEnvironmentManager) Delete(id dto.EnvironmentID) (bool, error) {
+	isFound, err := a.NextHandler().Delete(id)
+	if err != nil {
+		return false, fmt.Errorf("aws wraped: %w", err)
+	}
+	return isFound, nil
+}
+
+func (a *AWSEnvironmentManager) Statistics() map[dto.EnvironmentID]*dto.StatisticalExecutionEnvironmentData {
+	return a.NextHandler().Statistics()
+}
diff --git a/internal/environment/manager.go b/internal/environment/manager.go
index d9e3c5d..1ee9de2 100644
--- a/internal/environment/manager.go
+++ b/internal/environment/manager.go
@@ -1,30 +1,20 @@
 package environment
 
 import (
-	_ "embed"
-	"fmt"
-	"github.com/hashicorp/nomad/nomad/structs"
-	"github.com/openHPI/poseidon/internal/nomad"
 	"github.com/openHPI/poseidon/internal/runner"
 	"github.com/openHPI/poseidon/pkg/dto"
-	"github.com/openHPI/poseidon/pkg/logging"
-	"os"
 )
 
-// templateEnvironmentJobHCL holds our default job in HCL format.
-// The default job is used when creating new job and provides
-// common settings that all the jobs share.
-//go:embed template-environment-job.hcl
-var templateEnvironmentJobHCL string
-
-var log = logging.GetLogger("environment")
+// ManagerHandler is one handler in the chain of responsibility of environment managers.
+// Each manager can handle different requests.
+type ManagerHandler interface {
+	Manager
+	SetNextHandler(next ManagerHandler)
+	NextHandler() ManagerHandler
+}
 
 // Manager encapsulates API calls to the executor API for creation and deletion of execution environments.
 type Manager interface {
-	// Load fetches all already created execution environments from the executor and registers them at the runner manager.
-	// It should be called during the startup process (e.g. on creation of the Manager).
-	Load() error
-
 	// List returns all environments known by Poseidon.
 	// When `fetch` is set the environments are fetched from the executor before returning.
 	List(fetch bool) ([]runner.ExecutionEnvironment, error)
@@ -48,185 +38,3 @@ type Manager interface {
 	// Statistics returns statistical data for each execution environment.
 	Statistics() map[dto.EnvironmentID]*dto.StatisticalExecutionEnvironmentData
 }
-
-type NomadEnvironmentManager struct {
-	runnerManager          runner.Manager
-	api                    nomad.ExecutorAPI
-	templateEnvironmentHCL string
-}
-
-func NewNomadEnvironmentManager(
-	runnerManager runner.Manager,
-	apiClient nomad.ExecutorAPI,
-	templateJobFile string,
-) (*NomadEnvironmentManager, error) {
-	if err := loadTemplateEnvironmentJobHCL(templateJobFile); err != nil {
-		return nil, err
-	}
-
-	m := &NomadEnvironmentManager{runnerManager, apiClient, templateEnvironmentJobHCL}
-	if err := m.Load(); err != nil {
-		log.WithError(err).Error("Error recovering the execution environments")
-	}
-	runnerManager.Load()
-	return m, nil
-}
-
-func (m *NomadEnvironmentManager) Get(id dto.EnvironmentID, fetch bool) (
-	executionEnvironment runner.ExecutionEnvironment, err error) {
-	executionEnvironment, ok := m.runnerManager.GetEnvironment(id)
-
-	if fetch {
-		fetchedEnvironment, err := fetchEnvironment(id, m.api)
-		switch {
-		case err != nil:
-			return nil, err
-		case fetchedEnvironment == nil:
-			_, err = m.Delete(id)
-			if err != nil {
-				return nil, err
-			}
-			ok = false
-		case !ok:
-			m.runnerManager.StoreEnvironment(fetchedEnvironment)
-			executionEnvironment = fetchedEnvironment
-			ok = true
-		default:
-			executionEnvironment.SetConfigFrom(fetchedEnvironment)
-		}
-	}
-
-	if !ok {
-		err = runner.ErrUnknownExecutionEnvironment
-	}
-	return executionEnvironment, err
-}
-
-func (m *NomadEnvironmentManager) List(fetch bool) ([]runner.ExecutionEnvironment, error) {
-	if fetch {
-		err := m.Load()
-		if err != nil {
-			return nil, err
-		}
-	}
-	return m.runnerManager.ListEnvironments(), nil
-}
-
-func (m *NomadEnvironmentManager) CreateOrUpdate(id dto.EnvironmentID, request dto.ExecutionEnvironmentRequest) (
-	created bool, err error) {
-	// Check if execution environment is already existing (in the local memory).
-	environment, isExistingEnvironment := m.runnerManager.GetEnvironment(id)
-	if isExistingEnvironment {
-		// Remove existing environment to force downloading the newest Docker image.
-		// See https://github.com/openHPI/poseidon/issues/69
-		err = environment.Delete(m.api)
-		if err != nil {
-			return false, fmt.Errorf("failed to remove the environment: %w", err)
-		}
-	}
-
-	// Create a new environment with the given request options.
-	environment, err = NewNomadEnvironmentFromRequest(m.templateEnvironmentHCL, id, request)
-	if err != nil {
-		return false, fmt.Errorf("error creating Nomad environment: %w", err)
-	}
-
-	// Keep a copy of environment specification in memory.
-	m.runnerManager.StoreEnvironment(environment)
-
-	// Register template Job with Nomad.
-	err = environment.Register(m.api)
-	if err != nil {
-		return false, fmt.Errorf("error registering template job in API: %w", err)
-	}
-
-	// Launch idle runners based on the template job.
-	err = environment.ApplyPrewarmingPoolSize(m.api)
-	if err != nil {
-		return false, fmt.Errorf("error scaling template job in API: %w", err)
-	}
-
-	return !isExistingEnvironment, nil
-}
-
-func (m *NomadEnvironmentManager) Delete(id dto.EnvironmentID) (bool, error) {
-	executionEnvironment, ok := m.runnerManager.GetEnvironment(id)
-	if !ok {
-		return false, nil
-	}
-	m.runnerManager.DeleteEnvironment(id)
-	err := executionEnvironment.Delete(m.api)
-	if err != nil {
-		return true, fmt.Errorf("could not delete environment: %w", err)
-	}
-	return true, nil
-}
-
-func (m *NomadEnvironmentManager) Statistics() map[dto.EnvironmentID]*dto.StatisticalExecutionEnvironmentData {
-	return m.runnerManager.EnvironmentStatistics()
-}
-
-func (m *NomadEnvironmentManager) Load() error {
-	templateJobs, err := m.api.LoadEnvironmentJobs()
-	if err != nil {
-		return fmt.Errorf("couldn't load template jobs: %w", err)
-	}
-
-	for _, job := range templateJobs {
-		jobLogger := log.WithField("jobID", *job.ID)
-		if *job.Status != structs.JobStatusRunning {
-			jobLogger.Info("Job not running, skipping ...")
-			continue
-		}
-		configTaskGroup := nomad.FindAndValidateConfigTaskGroup(job)
-		if configTaskGroup == nil {
-			jobLogger.Info("Couldn't find config task group in job, skipping ...")
-			continue
-		}
-		environment := &NomadEnvironment{
-			jobHCL:      templateEnvironmentJobHCL,
-			job:         job,
-			idleRunners: runner.NewLocalRunnerStorage(),
-		}
-		m.runnerManager.StoreEnvironment(environment)
-		jobLogger.Info("Successfully recovered environment")
-	}
-	return nil
-}
-
-// loadTemplateEnvironmentJobHCL loads the template environment job HCL from the given path.
-// If the path is empty, the embedded default file is used.
-func loadTemplateEnvironmentJobHCL(path string) error {
-	if path == "" {
-		return nil
-	}
-	data, err := os.ReadFile(path)
-	if err != nil {
-		return fmt.Errorf("error loading template environment job: %w", err)
-	}
-	templateEnvironmentJobHCL = string(data)
-	return nil
-}
-
-func fetchEnvironment(id dto.EnvironmentID, apiClient nomad.ExecutorAPI) (runner.ExecutionEnvironment, error) {
-	environments, err := apiClient.LoadEnvironmentJobs()
-	if err != nil {
-		return nil, fmt.Errorf("error fetching the environment jobs: %w", err)
-	}
-	var fetchedEnvironment runner.ExecutionEnvironment
-	for _, job := range environments {
-		environmentID, err := nomad.EnvironmentIDFromTemplateJobID(*job.ID)
-		if err != nil {
-			log.WithError(err).Warn("Cannot parse environment id of loaded environment")
-			continue
-		}
-		if id == environmentID {
-			fetchedEnvironment = &NomadEnvironment{
-				jobHCL:      templateEnvironmentJobHCL,
-				job:         job,
-				idleRunners: runner.NewLocalRunnerStorage(),
-			}
-		}
-	}
-	return fetchedEnvironment, nil
-}
diff --git a/internal/environment/manager_mock.go b/internal/environment/manager_handler_mock.go
similarity index 70%
rename from internal/environment/manager_mock.go
rename to internal/environment/manager_handler_mock.go
index 6f4e0c4..d81d4e0 100644
--- a/internal/environment/manager_mock.go
+++ b/internal/environment/manager_handler_mock.go
@@ -9,13 +9,13 @@ import (
 	runner "github.com/openHPI/poseidon/internal/runner"
 )
 
-// ManagerMock is an autogenerated mock type for the Manager type
-type ManagerMock struct {
+// ManagerHandlerMock is an autogenerated mock type for the ManagerHandler type
+type ManagerHandlerMock struct {
 	mock.Mock
 }
 
 // CreateOrUpdate provides a mock function with given fields: id, request
-func (_m *ManagerMock) CreateOrUpdate(id dto.EnvironmentID, request dto.ExecutionEnvironmentRequest) (bool, error) {
+func (_m *ManagerHandlerMock) CreateOrUpdate(id dto.EnvironmentID, request dto.ExecutionEnvironmentRequest) (bool, error) {
 	ret := _m.Called(id, request)
 
 	var r0 bool
@@ -36,7 +36,7 @@ func (_m *ManagerMock) CreateOrUpdate(id dto.EnvironmentID, request dto.Executio
 }
 
 // Delete provides a mock function with given fields: id
-func (_m *ManagerMock) Delete(id dto.EnvironmentID) (bool, error) {
+func (_m *ManagerHandlerMock) Delete(id dto.EnvironmentID) (bool, error) {
 	ret := _m.Called(id)
 
 	var r0 bool
@@ -57,7 +57,7 @@ func (_m *ManagerMock) Delete(id dto.EnvironmentID) (bool, error) {
 }
 
 // Get provides a mock function with given fields: id, fetch
-func (_m *ManagerMock) Get(id dto.EnvironmentID, fetch bool) (runner.ExecutionEnvironment, error) {
+func (_m *ManagerHandlerMock) Get(id dto.EnvironmentID, fetch bool) (runner.ExecutionEnvironment, error) {
 	ret := _m.Called(id, fetch)
 
 	var r0 runner.ExecutionEnvironment
@@ -80,7 +80,7 @@ func (_m *ManagerMock) Get(id dto.EnvironmentID, fetch bool) (runner.ExecutionEn
 }
 
 // List provides a mock function with given fields: fetch
-func (_m *ManagerMock) List(fetch bool) ([]runner.ExecutionEnvironment, error) {
+func (_m *ManagerHandlerMock) List(fetch bool) ([]runner.ExecutionEnvironment, error) {
 	ret := _m.Called(fetch)
 
 	var r0 []runner.ExecutionEnvironment
@@ -102,22 +102,29 @@ func (_m *ManagerMock) List(fetch bool) ([]runner.ExecutionEnvironment, error) {
 	return r0, r1
 }
 
-// Load provides a mock function with given fields:
-func (_m *ManagerMock) Load() error {
+// NextHandler provides a mock function with given fields:
+func (_m *ManagerHandlerMock) NextHandler() ManagerHandler {
 	ret := _m.Called()
 
-	var r0 error
-	if rf, ok := ret.Get(0).(func() error); ok {
+	var r0 ManagerHandler
+	if rf, ok := ret.Get(0).(func() ManagerHandler); ok {
 		r0 = rf()
 	} else {
-		r0 = ret.Error(0)
+		if ret.Get(0) != nil {
+			r0 = ret.Get(0).(ManagerHandler)
+		}
 	}
 
 	return r0
 }
 
+// SetNextHandler provides a mock function with given fields: m
+func (_m *ManagerHandlerMock) SetNextHandler(m ManagerHandler) {
+	_m.Called(m)
+}
+
 // Statistics provides a mock function with given fields:
-func (_m *ManagerMock) Statistics() map[dto.EnvironmentID]*dto.StatisticalExecutionEnvironmentData {
+func (_m *ManagerHandlerMock) Statistics() map[dto.EnvironmentID]*dto.StatisticalExecutionEnvironmentData {
 	ret := _m.Called()
 
 	var r0 map[dto.EnvironmentID]*dto.StatisticalExecutionEnvironmentData
diff --git a/internal/environment/nomad_manager.go b/internal/environment/nomad_manager.go
new file mode 100644
index 0000000..5a839d3
--- /dev/null
+++ b/internal/environment/nomad_manager.go
@@ -0,0 +1,204 @@
+package environment
+
+import (
+	_ "embed"
+	"fmt"
+	"github.com/hashicorp/nomad/nomad/structs"
+	"github.com/openHPI/poseidon/internal/nomad"
+	"github.com/openHPI/poseidon/internal/runner"
+	"github.com/openHPI/poseidon/pkg/dto"
+	"github.com/openHPI/poseidon/pkg/logging"
+	"os"
+)
+
+// templateEnvironmentJobHCL holds our default job in HCL format.
+// The default job is used when creating new job and provides
+// common settings that all the jobs share.
+//go:embed template-environment-job.hcl
+var templateEnvironmentJobHCL string
+
+var log = logging.GetLogger("environment")
+
+type NomadEnvironmentManager struct {
+	*AbstractManager
+	runnerManager          runner.Manager
+	api                    nomad.ExecutorAPI
+	templateEnvironmentHCL string
+}
+
+func NewNomadEnvironmentManager(
+	runnerManager runner.Manager,
+	apiClient nomad.ExecutorAPI,
+	templateJobFile string,
+) (*NomadEnvironmentManager, error) {
+	if err := loadTemplateEnvironmentJobHCL(templateJobFile); err != nil {
+		return nil, err
+	}
+
+	m := &NomadEnvironmentManager{&AbstractManager{nil}, runnerManager,
+		apiClient, templateEnvironmentJobHCL}
+	if err := m.Load(); err != nil {
+		log.WithError(err).Error("Error recovering the execution environments")
+	}
+	runnerManager.Load()
+	return m, nil
+}
+
+func (m *NomadEnvironmentManager) Get(id dto.EnvironmentID, fetch bool) (
+	executionEnvironment runner.ExecutionEnvironment, err error) {
+	executionEnvironment, ok := m.runnerManager.GetEnvironment(id)
+
+	if fetch {
+		fetchedEnvironment, err := fetchEnvironment(id, m.api)
+		switch {
+		case err != nil:
+			return nil, err
+		case fetchedEnvironment == nil:
+			_, err = m.Delete(id)
+			if err != nil {
+				return nil, err
+			}
+			ok = false
+		case !ok:
+			m.runnerManager.StoreEnvironment(fetchedEnvironment)
+			executionEnvironment = fetchedEnvironment
+			ok = true
+		default:
+			executionEnvironment.SetConfigFrom(fetchedEnvironment)
+		}
+	}
+
+	if !ok {
+		err = runner.ErrUnknownExecutionEnvironment
+	}
+	return executionEnvironment, err
+}
+
+func (m *NomadEnvironmentManager) List(fetch bool) ([]runner.ExecutionEnvironment, error) {
+	if fetch {
+		err := m.Load()
+		if err != nil {
+			return nil, err
+		}
+	}
+	return m.runnerManager.ListEnvironments(), nil
+}
+
+func (m *NomadEnvironmentManager) CreateOrUpdate(id dto.EnvironmentID, request dto.ExecutionEnvironmentRequest) (
+	created bool, err error) {
+	// Check if execution environment is already existing (in the local memory).
+	environment, isExistingEnvironment := m.runnerManager.GetEnvironment(id)
+	if isExistingEnvironment {
+		// Remove existing environment to force downloading the newest Docker image.
+		// See https://github.com/openHPI/poseidon/issues/69
+		err = environment.Delete(m.api)
+		if err != nil {
+			return false, fmt.Errorf("failed to remove the environment: %w", err)
+		}
+	}
+
+	// Create a new environment with the given request options.
+	environment, err = NewNomadEnvironmentFromRequest(m.templateEnvironmentHCL, id, request)
+	if err != nil {
+		return false, fmt.Errorf("error creating Nomad environment: %w", err)
+	}
+
+	// Keep a copy of environment specification in memory.
+	m.runnerManager.StoreEnvironment(environment)
+
+	// Register template Job with Nomad.
+	err = environment.Register(m.api)
+	if err != nil {
+		return false, fmt.Errorf("error registering template job in API: %w", err)
+	}
+
+	// Launch idle runners based on the template job.
+	err = environment.ApplyPrewarmingPoolSize(m.api)
+	if err != nil {
+		return false, fmt.Errorf("error scaling template job in API: %w", err)
+	}
+
+	return !isExistingEnvironment, nil
+}
+
+func (m *NomadEnvironmentManager) Delete(id dto.EnvironmentID) (bool, error) {
+	executionEnvironment, ok := m.runnerManager.GetEnvironment(id)
+	if !ok {
+		return false, nil
+	}
+	m.runnerManager.DeleteEnvironment(id)
+	err := executionEnvironment.Delete(m.api)
+	if err != nil {
+		return true, fmt.Errorf("could not delete environment: %w", err)
+	}
+	return true, nil
+}
+
+func (m *NomadEnvironmentManager) Statistics() map[dto.EnvironmentID]*dto.StatisticalExecutionEnvironmentData {
+	return m.runnerManager.EnvironmentStatistics()
+}
+
+func (m *NomadEnvironmentManager) Load() error {
+	templateJobs, err := m.api.LoadEnvironmentJobs()
+	if err != nil {
+		return fmt.Errorf("couldn't load template jobs: %w", err)
+	}
+
+	for _, job := range templateJobs {
+		jobLogger := log.WithField("jobID", *job.ID)
+		if *job.Status != structs.JobStatusRunning {
+			jobLogger.Info("Job not running, skipping ...")
+			continue
+		}
+		configTaskGroup := nomad.FindAndValidateConfigTaskGroup(job)
+		if configTaskGroup == nil {
+			jobLogger.Info("Couldn't find config task group in job, skipping ...")
+			continue
+		}
+		environment := &NomadEnvironment{
+			jobHCL:      templateEnvironmentJobHCL,
+			job:         job,
+			idleRunners: runner.NewLocalRunnerStorage(),
+		}
+		m.runnerManager.StoreEnvironment(environment)
+		jobLogger.Info("Successfully recovered environment")
+	}
+	return nil
+}
+
+// loadTemplateEnvironmentJobHCL loads the template environment job HCL from the given path.
+// If the path is empty, the embedded default file is used.
+func loadTemplateEnvironmentJobHCL(path string) error {
+	if path == "" {
+		return nil
+	}
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return fmt.Errorf("error loading template environment job: %w", err)
+	}
+	templateEnvironmentJobHCL = string(data)
+	return nil
+}
+
+func fetchEnvironment(id dto.EnvironmentID, apiClient nomad.ExecutorAPI) (runner.ExecutionEnvironment, error) {
+	environments, err := apiClient.LoadEnvironmentJobs()
+	if err != nil {
+		return nil, fmt.Errorf("error fetching the environment jobs: %w", err)
+	}
+	var fetchedEnvironment runner.ExecutionEnvironment
+	for _, job := range environments {
+		environmentID, err := nomad.EnvironmentIDFromTemplateJobID(*job.ID)
+		if err != nil {
+			log.WithError(err).Warn("Cannot parse environment id of loaded environment")
+			continue
+		}
+		if id == environmentID {
+			fetchedEnvironment = &NomadEnvironment{
+				jobHCL:      templateEnvironmentJobHCL,
+				job:         job,
+				idleRunners: runner.NewLocalRunnerStorage(),
+			}
+		}
+	}
+	return fetchedEnvironment, nil
+}
diff --git a/internal/environment/manager_test.go b/internal/environment/nomad_manager_test.go
similarity index 100%
rename from internal/environment/manager_test.go
rename to internal/environment/nomad_manager_test.go
diff --git a/internal/runner/abstract_manager.go b/internal/runner/abstract_manager.go
new file mode 100644
index 0000000..a409a4f
--- /dev/null
+++ b/internal/runner/abstract_manager.go
@@ -0,0 +1,52 @@
+package runner
+
+import (
+	"errors"
+	"github.com/openHPI/poseidon/pkg/dto"
+)
+
+var ErrNullObject = errors.New("functionality not available for the null object")
+
+// AbstractManager is used to have a fallback runner manager in the chain of responsibility
+// following the null object pattern.
+type AbstractManager struct {
+	nextHandler AccessorHandler
+}
+
+func (n *AbstractManager) SetNextHandler(next AccessorHandler) {
+	n.nextHandler = next
+}
+
+func (n *AbstractManager) NextHandler() AccessorHandler {
+	return n.nextHandler
+}
+
+func (n *AbstractManager) ListEnvironments() []ExecutionEnvironment {
+	return []ExecutionEnvironment{}
+}
+
+func (n *AbstractManager) GetEnvironment(_ dto.EnvironmentID) (ExecutionEnvironment, bool) {
+	return nil, false
+}
+
+func (n *AbstractManager) StoreEnvironment(_ ExecutionEnvironment) {}
+
+func (n *AbstractManager) DeleteEnvironment(_ dto.EnvironmentID) {}
+
+func (n *AbstractManager) EnvironmentStatistics() map[dto.EnvironmentID]*dto.StatisticalExecutionEnvironmentData {
+	return map[dto.EnvironmentID]*dto.StatisticalExecutionEnvironmentData{}
+}
+
+func (n *AbstractManager) Claim(_ dto.EnvironmentID, _ int) (Runner, error) {
+	return nil, ErrNullObject
+}
+
+func (n *AbstractManager) Get(_ string) (Runner, error) {
+	return nil, ErrNullObject
+}
+
+func (n *AbstractManager) Return(_ Runner) error {
+	return nil
+}
+
+func (n *AbstractManager) Load() {}
diff --git a/internal/runner/aws_manager.go b/internal/runner/aws_manager.go
new file mode 100644
index 0000000..25e0322
--- /dev/null
+++ b/internal/runner/aws_manager.go
@@ -0,0 +1,57 @@
+package runner
+
+import (
+	"fmt"
+	"github.com/openHPI/poseidon/pkg/dto"
+)
+
+type AWSRunnerManager struct {
+	*AbstractManager
+}
+
+// NewAWSRunnerManager creates a new runner manager that keeps track of all runners at AWS.
+func NewAWSRunnerManager() *AWSRunnerManager {
+	return &AWSRunnerManager{&AbstractManager{}}
+}
+
+func (a AWSRunnerManager) ListEnvironments() []ExecutionEnvironment {
+	return []ExecutionEnvironment{}
+}
+
+func (a AWSRunnerManager) GetEnvironment(_ dto.EnvironmentID) (ExecutionEnvironment, bool) {
+	return nil, false
+}
+
+func (a AWSRunnerManager) StoreEnvironment(_ ExecutionEnvironment) {}
+
+func (a AWSRunnerManager) DeleteEnvironment(_ dto.EnvironmentID) {}
+
+func (a AWSRunnerManager) EnvironmentStatistics() map[dto.EnvironmentID]*dto.StatisticalExecutionEnvironmentData {
+	return map[dto.EnvironmentID]*dto.StatisticalExecutionEnvironmentData{}
+}
+
+func (a AWSRunnerManager) Claim(id dto.EnvironmentID, duration int) (Runner, error) {
+	r, err := a.NextHandler().Claim(id, duration)
+	if err != nil {
+		return nil, fmt.Errorf("aws wraped: %w", err)
+	}
+	return r, nil
+}
+
+func (a AWSRunnerManager) Get(runnerID string) (Runner, error) {
+	r, err := a.NextHandler().Get(runnerID)
+	if err != nil {
+		return nil, fmt.Errorf("aws wraped: %w", err)
+	}
+	return r, nil
+}
+
+func (a AWSRunnerManager) Return(r Runner) error {
+	err := a.NextHandler().Return(r)
+	if err != nil {
+		return fmt.Errorf("aws wraped: %w", err)
+	}
+	return nil
+}
+
+func (a AWSRunnerManager) Load() {}
diff --git a/internal/runner/inactivity_timer.go b/internal/runner/inactivity_timer.go
index e9d1dce..eafee28 100644
--- a/internal/runner/inactivity_timer.go
+++ b/internal/runner/inactivity_timer.go
@@ -37,11 +37,11 @@ type InactivityTimerImplementation struct {
 	duration time.Duration
 	state    TimerState
 	runner   Runner
-	manager  Manager
+	manager  Accessor
 	mu       sync.Mutex
 }
 
-func NewInactivityTimer(runner Runner, manager Manager) InactivityTimer {
+func NewInactivityTimer(runner Runner, manager Accessor) InactivityTimer {
 	return &InactivityTimerImplementation{
 		state:   TimerInactive,
 		runner:  runner,
diff --git a/internal/runner/manager.go b/internal/runner/manager.go
index 8832ab3..b09a331 100644
--- a/internal/runner/manager.go
+++ b/internal/runner/manager.go
@@ -1,24 +1,9 @@
 package runner
 
 import (
-	"context"
 	"encoding/json"
-	"errors"
-	"fmt"
-	nomadApi "github.com/hashicorp/nomad/api"
 	"github.com/openHPI/poseidon/internal/nomad"
 	"github.com/openHPI/poseidon/pkg/dto"
-	"github.com/openHPI/poseidon/pkg/logging"
-	"github.com/sirupsen/logrus"
-	"strconv"
-	"time"
-)
-
-var (
-	log                            = logging.GetLogger("runner")
-	ErrUnknownExecutionEnvironment = errors.New("execution environment not found")
-	ErrNoRunnersAvailable          = errors.New("no runners available for this execution environment")
-	ErrRunnerNotFound              = errors.New("no runner found with this id")
 )
 
 // ExecutionEnvironment are groups of runner that share the configuration stored in the environment.
@@ -67,6 +52,12 @@ type ExecutionEnvironment interface {
 // Manager keeps track of the used and unused runners of all execution environments in order to provide unused
 // runners to new clients and ensure no runner is used twice.
 type Manager interface {
+	EnvironmentAccessor
+	AccessorHandler
+}
+
+// EnvironmentAccessor provides access to the stored environments.
+type EnvironmentAccessor interface {
 	// ListEnvironments returns all execution environments known by Poseidon.
 	ListEnvironments() []ExecutionEnvironment
 
@@ -83,7 +74,18 @@ type Manager interface {
 
 	// EnvironmentStatistics returns statistical data for each execution environment.
 	EnvironmentStatistics() map[dto.EnvironmentID]*dto.StatisticalExecutionEnvironmentData
+}
 
+// AccessorHandler is one handler in te chain of responsibility of runner accessors.
+// Each runner accessor can handle different requests.
+type AccessorHandler interface {
+	Accessor
+	SetNextHandler(m AccessorHandler)
+	NextHandler() AccessorHandler
+}
+
+// Accessor manages the lifecycle of Runner.
+type Accessor interface {
 	// Claim returns a new runner. The runner is deleted after duration seconds if duration is not 0.
 	// It makes sure that the runner is not in use yet and returns an error if no runner could be provided.
 	Claim(id dto.EnvironmentID, duration int) (Runner, error)
@@ -100,201 +102,3 @@ type Manager interface {
 	// It should be called during the startup process (e.g. on creation of the Manager).
 	Load()
 }
-
-type NomadRunnerManager struct {
-	apiClient    nomad.ExecutorAPI
-	environments EnvironmentStorage
-	usedRunners  Storage
-}
-
-// NewNomadRunnerManager creates a new runner manager that keeps track of all runners.
-// It uses the apiClient for all requests and runs a background task to keep the runners in sync with Nomad.
-// If you cancel the context the background synchronization will be stopped.
-func NewNomadRunnerManager(apiClient nomad.ExecutorAPI, ctx context.Context) *NomadRunnerManager {
-	m := &NomadRunnerManager{
-		apiClient,
-		NewLocalEnvironmentStorage(),
-		NewLocalRunnerStorage(),
-	}
-	go m.keepRunnersSynced(ctx)
-	return m
-}
-
-func (m *NomadRunnerManager) ListEnvironments() []ExecutionEnvironment {
-	return m.environments.List()
-}
-
-func (m *NomadRunnerManager) GetEnvironment(id dto.EnvironmentID) (ExecutionEnvironment, bool) {
-	return m.environments.Get(id)
-}
-
-func (m *NomadRunnerManager) StoreEnvironment(environment ExecutionEnvironment) {
-	m.environments.Add(environment)
-}
-
-func (m *NomadRunnerManager) DeleteEnvironment(id dto.EnvironmentID) {
-	m.environments.Delete(id)
-}
-
-func (m *NomadRunnerManager) EnvironmentStatistics() map[dto.EnvironmentID]*dto.StatisticalExecutionEnvironmentData {
-	environments := make(map[dto.EnvironmentID]*dto.StatisticalExecutionEnvironmentData)
-	for _, e := range m.environments.List() {
-		environments[e.ID()] = &dto.StatisticalExecutionEnvironmentData{
-			ID:                 int(e.ID()),
-			PrewarmingPoolSize: e.PrewarmingPoolSize(),
-			IdleRunners:        uint(e.IdleRunnerCount()),
-			UsedRunners:        0,
-		}
-	}
-
-	for _, r := range m.usedRunners.List() {
-		id, err := nomad.EnvironmentIDFromRunnerID(r.ID())
-		if err != nil {
-			log.WithError(err).Error("Stored runners must have correct IDs")
-		}
-		environments[id].UsedRunners++
-	}
-	return environments
-}
-
-func (m *NomadRunnerManager) Claim(environmentID dto.EnvironmentID, duration int) (Runner, error) {
-	environment, ok := m.environments.Get(environmentID)
-	if !ok {
-		return nil, ErrUnknownExecutionEnvironment
-	}
-	runner, ok := environment.Sample(m.apiClient)
-	if !ok {
-		return nil, ErrNoRunnersAvailable
-	}
-
-	m.usedRunners.Add(runner)
-	go m.markRunnerAsUsed(runner, duration)
-
-	runner.SetupTimeout(time.Duration(duration) * time.Second)
-	return runner, nil
-}
-
-func (m *NomadRunnerManager) markRunnerAsUsed(runner Runner, timeoutDuration int) {
-	err := m.apiClient.MarkRunnerAsUsed(runner.ID(), timeoutDuration)
-	if err != nil {
-		err = m.Return(runner)
-		if err != nil {
-			log.WithError(err).WithField("runnerID", runner.ID()).Error("can't mark runner as used and can't return runner")
-		}
-	}
-}
-
-func (m *NomadRunnerManager) Get(runnerID string) (Runner, error) {
-	runner, ok := m.usedRunners.Get(runnerID)
-	if !ok {
-		return nil, ErrRunnerNotFound
-	}
-	return runner, nil
-}
-
-func (m *NomadRunnerManager) Return(r Runner) error {
-	r.StopTimeout()
-	err := m.apiClient.DeleteJob(r.ID())
-	if err != nil {
-		return fmt.Errorf("error deleting runner in Nomad: %w", err)
-	}
-	m.usedRunners.Delete(r.ID())
-	return nil
-}
-
-func (m *NomadRunnerManager) Load() {
-	for _, environment := range m.environments.List() {
-		environmentLogger := log.WithField("environmentID", environment.ID())
-		runnerJobs, err := m.apiClient.LoadRunnerJobs(environment.ID())
-		if err != nil {
-			environmentLogger.WithError(err).Warn("Error fetching the runner jobs")
-		}
-		for _, job := range runnerJobs {
-			m.loadSingleJob(job, environmentLogger, environment)
-		}
-		err = environment.ApplyPrewarmingPoolSize(m.apiClient)
-		if err != nil {
-			environmentLogger.WithError(err).Error("Couldn't scale environment")
-		}
-	}
-}
-
-func (m *NomadRunnerManager) loadSingleJob(job *nomadApi.Job, environmentLogger *logrus.Entry,
-	environment ExecutionEnvironment) {
-	configTaskGroup := nomad.FindTaskGroup(job, nomad.ConfigTaskGroupName)
-	if configTaskGroup == nil {
-		environmentLogger.Infof("Couldn't find config task group in job %s, skipping ...", *job.ID)
-		return
-	}
-	isUsed := configTaskGroup.Meta[nomad.ConfigMetaUsedKey] == nomad.ConfigMetaUsedValue
-	portMappings, err := m.apiClient.LoadRunnerPortMappings(*job.ID)
-	if err != nil {
-		environmentLogger.WithError(err).Warn("Error loading runner portMappings")
-		return
-	}
-	newJob := NewNomadJob(*job.ID, portMappings, m.apiClient, m)
-	if isUsed {
-		m.usedRunners.Add(newJob)
-		timeout, err := strconv.Atoi(configTaskGroup.Meta[nomad.ConfigMetaTimeoutKey])
-		if err != nil {
-			environmentLogger.WithError(err).Warn("Error loading timeout from meta values")
-		} else {
-			newJob.SetupTimeout(time.Duration(timeout) * time.Second)
-		}
-	} else {
-		environment.AddRunner(newJob)
-	}
-}
-
-func (m *NomadRunnerManager) keepRunnersSynced(ctx context.Context) {
-	retries := 0
-	for ctx.Err() == nil {
-		err := m.apiClient.WatchEventStream(ctx, m.onAllocationAdded, m.onAllocationStopped)
-		retries += 1
-		log.WithError(err).Errorf("Stopped updating the runners! Retry %v", retries)
-		<-time.After(time.Second)
-	}
-}
-
-func (m *NomadRunnerManager) onAllocationAdded(alloc *nomadApi.Allocation) {
-	log.WithField("id", alloc.JobID).Debug("Runner started")
-
-	if nomad.IsEnvironmentTemplateID(alloc.JobID) {
-		return
-	}
-
-	environmentID, err := nomad.EnvironmentIDFromRunnerID(alloc.JobID)
-	if err != nil {
-		log.WithError(err).Warn("Allocation could not be added")
-		return
-	}
-
-	environment, ok := m.environments.Get(environmentID)
-	if ok {
-		var mappedPorts []nomadApi.PortMapping
-		if alloc.AllocatedResources != nil {
-			mappedPorts = alloc.AllocatedResources.Shared.Ports
-		}
-		environment.AddRunner(NewNomadJob(alloc.JobID, mappedPorts, m.apiClient, m))
-	}
-}
-
-func (m *NomadRunnerManager) onAllocationStopped(alloc *nomadApi.Allocation) {
-	log.WithField("id", alloc.JobID).Debug("Runner stopped")
-
-	if nomad.IsEnvironmentTemplateID(alloc.JobID) {
-		return
-	}
-
-	environmentID, err := nomad.EnvironmentIDFromRunnerID(alloc.JobID)
-	if err != nil {
-		log.WithError(err).Warn("Stopped allocation can not be handled")
-		return
-	}
-
-	m.usedRunners.Delete(alloc.JobID)
-	environment, ok := m.environments.Get(environmentID)
-	if ok {
-		environment.DeleteRunner(alloc.JobID)
-	}
-}
diff --git a/internal/runner/manager_mock.go b/internal/runner/manager_mock.go
index f43c52f..a9e2602 100644
--- a/internal/runner/manager_mock.go
+++ b/internal/runner/manager_mock.go
@@ -123,6 +123,22 @@ func (_m *ManagerMock) Load() {
 	_m.Called()
 }
 
+// NextHandler provides a mock function with given fields:
+func (_m *ManagerMock) NextHandler() AccessorHandler {
+	ret := _m.Called()
+
+	var r0 AccessorHandler
+	if rf, ok := ret.Get(0).(func() AccessorHandler); ok {
+		r0 = rf()
+	} else {
+		if ret.Get(0) != nil {
+			r0 = ret.Get(0).(AccessorHandler)
+		}
+	}
+
+	return r0
+}
+
 // Return provides a mock function with given fields: r
 func (_m *ManagerMock) Return(r Runner) error {
 	ret := _m.Called(r)
@@ -137,6 +153,11 @@ func (_m *ManagerMock) Return(r Runner) error {
 	return r0
 }
 
+// SetNextHandler provides a mock function with given fields: m
+func (_m *ManagerMock) SetNextHandler(m AccessorHandler) {
+	_m.Called(m)
+}
+
 // StoreEnvironment provides a mock function with given fields: environment
 func (_m *ManagerMock) StoreEnvironment(environment ExecutionEnvironment) {
 	_m.Called(environment)
diff --git a/internal/runner/nomad_manager.go b/internal/runner/nomad_manager.go
new file mode 100644
index 0000000..b8da3cb
--- /dev/null
+++ b/internal/runner/nomad_manager.go
@@ -0,0 +1,221 @@
+package runner
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	nomadApi "github.com/hashicorp/nomad/api"
+	"github.com/openHPI/poseidon/internal/nomad"
+	"github.com/openHPI/poseidon/pkg/dto"
+	"github.com/openHPI/poseidon/pkg/logging"
+	"github.com/sirupsen/logrus"
+	"strconv"
+	"time"
+)
+
+var (
+	log                            = logging.GetLogger("runner")
+	ErrUnknownExecutionEnvironment = errors.New("execution environment not found")
+	ErrNoRunnersAvailable          = errors.New("no runners available for this execution environment")
+	ErrRunnerNotFound              = errors.New("no runner found with this id")
+)
+
+type NomadRunnerManager struct {
+	*AbstractManager
+	apiClient    nomad.ExecutorAPI
+	environments EnvironmentStorage
+	usedRunners  Storage
+}
+
+// NewNomadRunnerManager creates a new runner manager that keeps track of all runners.
+// It uses the apiClient for all requests and runs a background task to keep the runners in sync with Nomad.
+// If you cancel the context the background synchronization will be stopped.
+func NewNomadRunnerManager(apiClient nomad.ExecutorAPI, ctx context.Context) *NomadRunnerManager {
+	m := &NomadRunnerManager{
+		&AbstractManager{},
+		apiClient,
+		NewLocalEnvironmentStorage(),
+		NewLocalRunnerStorage(),
+	}
+	go m.keepRunnersSynced(ctx)
+	return m
+}
+
+func (m *NomadRunnerManager) ListEnvironments() []ExecutionEnvironment {
+	return m.environments.List()
+}
+
+func (m *NomadRunnerManager) GetEnvironment(id dto.EnvironmentID) (ExecutionEnvironment, bool) {
+	return m.environments.Get(id)
+}
+
+func (m *NomadRunnerManager) StoreEnvironment(environment ExecutionEnvironment) {
+	m.environments.Add(environment)
+}
+
+func (m *NomadRunnerManager) DeleteEnvironment(id dto.EnvironmentID) {
+	m.environments.Delete(id)
+}
+
+func (m *NomadRunnerManager) EnvironmentStatistics() map[dto.EnvironmentID]*dto.StatisticalExecutionEnvironmentData {
+	environments := make(map[dto.EnvironmentID]*dto.StatisticalExecutionEnvironmentData)
+	for _, e := range m.environments.List() {
+		environments[e.ID()] = &dto.StatisticalExecutionEnvironmentData{
+			ID:                 int(e.ID()),
+			PrewarmingPoolSize: e.PrewarmingPoolSize(),
+			IdleRunners:        uint(e.IdleRunnerCount()),
+			UsedRunners:        0,
+		}
+	}
+
+	for _, r := range m.usedRunners.List() {
+		id, err := nomad.EnvironmentIDFromRunnerID(r.ID())
+		if err != nil {
+			log.WithError(err).Error("Stored runners must have correct IDs")
+		}
+		environments[id].UsedRunners++
+	}
+	return environments
+}
+
+func (m *NomadRunnerManager) Claim(environmentID dto.EnvironmentID, duration int) (Runner, error) {
+	environment, ok := m.environments.Get(environmentID)
+	if !ok {
+		return nil, ErrUnknownExecutionEnvironment
+	}
+	runner, ok := environment.Sample(m.apiClient)
+	if !ok {
+		return nil, ErrNoRunnersAvailable
+	}
+
+	m.usedRunners.Add(runner)
+	go m.markRunnerAsUsed(runner, duration)
+
+	runner.SetupTimeout(time.Duration(duration) * time.Second)
+	return runner, nil
+}
+
+func (m *NomadRunnerManager) markRunnerAsUsed(runner Runner, timeoutDuration int) {
+	err := m.apiClient.MarkRunnerAsUsed(runner.ID(), timeoutDuration)
+	if err != nil {
+		err = m.Return(runner)
+		if err != nil {
+			log.WithError(err).WithField("runnerID", runner.ID()).Error("can't mark runner as used and can't return runner")
+		}
+	}
+}
+
+func (m *NomadRunnerManager) Get(runnerID string) (Runner, error) {
+	runner, ok := m.usedRunners.Get(runnerID)
+	if !ok {
+		return nil, ErrRunnerNotFound
+	}
+	return runner, nil
+}
+
+func (m *NomadRunnerManager) Return(r Runner) error {
+	r.StopTimeout()
+	err := m.apiClient.DeleteJob(r.ID())
+	if err != nil {
+		return fmt.Errorf("error deleting runner in Nomad: %w", err)
+	}
+	m.usedRunners.Delete(r.ID())
+	return nil
+}
+
+func (m *NomadRunnerManager) Load() {
+	for _, environment := range m.environments.List() {
+		environmentLogger := log.WithField("environmentID", environment.ID())
+		runnerJobs, err := m.apiClient.LoadRunnerJobs(environment.ID())
+		if err != nil {
+			environmentLogger.WithError(err).Warn("Error fetching the runner jobs")
+		}
+		for _, job := range runnerJobs {
+			m.loadSingleJob(job, environmentLogger, environment)
+		}
+		err = environment.ApplyPrewarmingPoolSize(m.apiClient)
+		if err != nil {
+			environmentLogger.WithError(err).Error("Couldn't scale environment")
+		}
+	}
+}
+
+func (m *NomadRunnerManager) loadSingleJob(job *nomadApi.Job, environmentLogger *logrus.Entry,
+	environment ExecutionEnvironment) {
+	configTaskGroup := nomad.FindTaskGroup(job, nomad.ConfigTaskGroupName)
+	if configTaskGroup == nil {
+		environmentLogger.Infof("Couldn't find config task group in job %s, skipping ...", *job.ID)
+		return
+	}
+	isUsed := configTaskGroup.Meta[nomad.ConfigMetaUsedKey] == nomad.ConfigMetaUsedValue
+	portMappings, err := m.apiClient.LoadRunnerPortMappings(*job.ID)
+	if err != nil {
+		environmentLogger.WithError(err).Warn("Error loading runner portMappings")
+		return
+	}
+	newJob := NewNomadJob(*job.ID, portMappings, m.apiClient, m)
+	if isUsed {
+		m.usedRunners.Add(newJob)
+		timeout, err := strconv.Atoi(configTaskGroup.Meta[nomad.ConfigMetaTimeoutKey])
+		if err != nil {
+			environmentLogger.WithError(err).Warn("Error loading timeout from meta values")
+		} else {
+			newJob.SetupTimeout(time.Duration(timeout) * time.Second)
+		}
+	} else {
+		environment.AddRunner(newJob)
+	}
+}
+
+func (m *NomadRunnerManager) keepRunnersSynced(ctx context.Context) {
+	retries := 0
+	for ctx.Err() == nil {
+		err := m.apiClient.WatchEventStream(ctx, m.onAllocationAdded, m.onAllocationStopped)
+		retries += 1
+		log.WithError(err).Errorf("Stopped updating the runners! Retry %v", retries)
+		<-time.After(time.Second)
+	}
+}
+
+func (m *NomadRunnerManager) onAllocationAdded(alloc *nomadApi.Allocation) {
+	log.WithField("id", alloc.JobID).Debug("Runner started")
+
+	if nomad.IsEnvironmentTemplateID(alloc.JobID) {
+		return
+	}
+
+	environmentID, err := nomad.EnvironmentIDFromRunnerID(alloc.JobID)
+	if err != nil {
+		log.WithError(err).Warn("Allocation could not be added")
+		return
+	}
+
+	environment, ok := m.environments.Get(environmentID)
+	if ok {
+		var mappedPorts []nomadApi.PortMapping
+		if alloc.AllocatedResources != nil {
+			mappedPorts = alloc.AllocatedResources.Shared.Ports
+		}
+		environment.AddRunner(NewNomadJob(alloc.JobID, mappedPorts, m.apiClient, m))
+	}
+}
+
+func (m *NomadRunnerManager) onAllocationStopped(alloc *nomadApi.Allocation) {
+	log.WithField("id", alloc.JobID).Debug("Runner stopped")
+
+	if nomad.IsEnvironmentTemplateID(alloc.JobID) {
+		return
+	}
+
+	environmentID, err := nomad.EnvironmentIDFromRunnerID(alloc.JobID)
+	if err != nil {
+		log.WithError(err).Warn("Stopped allocation can not be handled")
+		return
+	}
+
+	m.usedRunners.Delete(alloc.JobID)
+	environment, ok := m.environments.Get(environmentID)
+	if ok {
+		environment.DeleteRunner(alloc.JobID)
+	}
+}
diff --git a/internal/runner/manager_test.go b/internal/runner/nomad_manager_test.go
similarity index 100%
rename from internal/runner/manager_test.go
rename to internal/runner/nomad_manager_test.go
diff --git a/internal/runner/runner.go b/internal/runner/runner.go
index 7681c30..1c91104 100644
--- a/internal/runner/runner.go
+++ b/internal/runner/runner.go
@@ -79,12 +79,12 @@ type NomadJob struct {
 	id           string
 	portMappings []nomadApi.PortMapping
 	api          nomad.ExecutorAPI
-	manager      Manager
+	manager      Accessor
 }
 
 // NewNomadJob creates a new NomadJob with the provided id.
 func NewNomadJob(id string, portMappings []nomadApi.PortMapping,
-	apiClient nomad.ExecutorAPI, manager Manager,
+	apiClient nomad.ExecutorAPI, manager Accessor,
 ) *NomadJob {
 	job := &NomadJob{
 		id:           id,
diff --git a/internal/runner/runner_test.go b/internal/runner/runner_test.go
index 140c6e0..3d065e1 100644
--- a/internal/runner/runner_test.go
+++ b/internal/runner/runner_test.go
@@ -390,6 +390,6 @@ func (s *UpdateFileSystemTestSuite) readFilesFromTarArchive(tarArchive io.Reader
 }
 
 // NewRunner creates a new runner with the provided id and manager.
-func NewRunner(id string, manager Manager) Runner {
+func NewRunner(id string, manager Accessor) Runner {
 	return NewNomadJob(id, nil, nil, manager)
 }