diff --git a/server-go/http/collection.go b/server-go/http/collection.go
index 9adcdd8e..1800773d 100644
--- a/server-go/http/collection.go
+++ b/server-go/http/collection.go
@@ -6,6 +6,7 @@ import (
 	"github.com/gin-gonic/gin"
 	"github.com/riotkit-org/backup-repository/core"
 	"github.com/riotkit-org/backup-repository/security"
+	"github.com/sirupsen/logrus"
 	"io"
 	"time"
 )
@@ -15,8 +16,8 @@ func addUploadRoute(r *gin.RouterGroup, ctx *core.ApplicationContainer) {
 		// todo: check if rotation strategy allows uploading
 		// todo: deactivate token if temporary token is used
 		// todo: check uploaded file size, respect quotas and additional space
-		// todo: check if there are gpg header and footer
 		// todo: handle upload interruptions
+		// todo: locking support! There should be no concurrent uploads to the same collection
 
 		ctxUser, _ := GetContextUser(ctx, c)
 
@@ -49,6 +50,17 @@ func addUploadRoute(r *gin.RouterGroup, ctx *core.ApplicationContainer) {
 			return
 		}
 
+		// Check rotation strategy: Is it allowed to upload? Is there enough space?
+		rotationStrategyCase, strategyFactorialError := ctx.Storage.CreateRotationStrategyCase(collection)
+		if strategyFactorialError != nil {
+			logrus.Errorf(fmt.Sprintf("Cannot create collection strategy for collectionId=%v, error: %v", collection.Metadata.Name, strategyFactorialError))
+			ServerErrorResponse(c, errors.New("internal error while trying to create rotation strategy. Check server logs"))
+		}
+		if err := rotationStrategyCase.CanUpload(version); err != nil {
+			UnauthorizedResponse(c, errors.New(fmt.Sprintf("backup collection strategy declined a possibility to upload, %v", err)))
+			return
+		}
+
 		var stream io.ReadCloser
 
 		// Support form data
@@ -82,8 +94,11 @@ func addUploadRoute(r *gin.RouterGroup, ctx *core.ApplicationContainer) {
 		version.Filesize = wroteLen
 
 		// Append version to the registry
+		// todo
 		//ctx.Storage.SubmitVersion(version)
+		//ctx.Storage.CleanUpOlderVersions(rotationStrategyCase.GetVersionsThatShouldBeDeletedIfThisVersionUploaded(version))
 
+		// todo: Rotate collection
 		// todo: add UploadedVersion to database
 		OKResponse(c, gin.H{
 			"version": version,
diff --git a/server-go/storage/repository.go b/server-go/storage/repository.go
index bbd10181..291d140a 100644
--- a/server-go/storage/repository.go
+++ b/server-go/storage/repository.go
@@ -17,6 +17,16 @@ func (vr VersionsRepository) findLastHighestVersionNumber(collectionId string) (
 	return maxNum, nil
 }
 
+func (vr VersionsRepository) findAllVersionsForCollectionId(collectionId string) ([]UploadedVersion, error) {
+	var foundVersions []UploadedVersion
+
+	err := vr.db.Model(&UploadedVersion{}).Where("uploaded_versions.collection_id = ?", collectionId).Order("uploaded_versions.version_number DESC").Find(&foundVersions).Error
+	if err != nil {
+		return []UploadedVersion{}, err
+	}
+	return foundVersions, nil
+}
+
 func InitializeModel(db *gorm.DB) error {
 	return db.AutoMigrate(&UploadedVersion{})
 }
diff --git a/server-go/storage/rotation.go b/server-go/storage/rotation.go
new file mode 100644
index 00000000..1f878503
--- /dev/null
+++ b/server-go/storage/rotation.go
@@ -0,0 +1,51 @@
+package storage
+
+import (
+	"github.com/riotkit-org/backup-repository/collections"
+	"sort"
+)
+
+type RotationStrategy interface {
+	// CanUpload returns nil if YES, error if NO
+	CanUpload(version UploadedVersion) error
+
+	// GetVersionsThatShouldBeDeletedIfThisVersionUploaded lists all the versions that should be deleted if a new version would be submitted
+	GetVersionsThatShouldBeDeletedIfThisVersionUploaded(version UploadedVersion) []UploadedVersion
+}
+
+//
+// FifoRotationStrategy implements a simple queue, first is appended, oldest will be deleted
+//
+type FifoRotationStrategy struct {
+	collection       *collections.Collection
+	existingVersions []UploadedVersion
+}
+
+func (frs *FifoRotationStrategy) CanUpload(version UploadedVersion) error {
+	return nil
+}
+
+func (frs *FifoRotationStrategy) GetVersionsThatShouldBeDeletedIfThisVersionUploaded(version UploadedVersion) []UploadedVersion {
+	existingVersions := frs.existingVersions
+
+	// nothing to do, there is still enough slots
+	if len(existingVersions) < frs.collection.Spec.MaxBackupsCount {
+		return []UploadedVersion{}
+	}
+
+	// order by version number DESCENDING
+	sort.SliceStable(&existingVersions, func(i, j int) bool {
+		return existingVersions[i].VersionNumber > existingVersions[j].VersionNumber
+	})
+
+	// oldest element
+	return existingVersions[0:1]
+}
+
+// todo: test reference
+func NewFifoRotationStrategy(collection *collections.Collection, existingVersions []UploadedVersion) *FifoRotationStrategy {
+	return &FifoRotationStrategy{
+		collection:       collection,
+		existingVersions: existingVersions,
+	}
+}
diff --git a/server-go/storage/rotation_test.go b/server-go/storage/rotation_test.go
new file mode 100644
index 00000000..82be0547
--- /dev/null
+++ b/server-go/storage/rotation_test.go
@@ -0,0 +1 @@
+package storage
diff --git a/server-go/storage/service.go b/server-go/storage/service.go
index 5b4e9f35..da1366af 100644
--- a/server-go/storage/service.go
+++ b/server-go/storage/service.go
@@ -49,6 +49,19 @@ func (s *Service) CreateNewVersionFromCollection(c *collections.Collection, uplo
 	}, nil
 }
 
+func (s *Service) CreateRotationStrategyCase(collection *collections.Collection) (RotationStrategy, error) {
+	foundVersions, err := s.repository.findAllVersionsForCollectionId(collection.Metadata.Name)
+	if err != nil {
+		return &FifoRotationStrategy{}, errors.New(fmt.Sprintf("cannot construct rotation strategy, cannot findAllVersionsForCollectionId, error: %v", err))
+	}
+
+	if collection.Spec.StrategyName == "fifo" {
+		return NewFifoRotationStrategy(collection, foundVersions), nil
+	}
+
+	return &FifoRotationStrategy{}, errors.New(fmt.Sprintf("collection configuration error: unrecognized backup strategy type '%v'", collection.Spec.StrategyName))
+}
+
 // NewService is a factory method that knows how to construct a Storage provider, distincting multiple types of providers
 func NewService(db *gorm.DB, driverUrl string, isUsingGCS bool) (Service, error) {
 	repository := VersionsRepository{db: db}
@@ -74,6 +87,7 @@ func NewService(db *gorm.DB, driverUrl string, isUsingGCS bool) (Service, error)
 		return Service{storage: driver, repository: &repository}, nil
 	}
 
+	// AWS S3, Min.io, CEPH and others compatible with S3 protocol
 	driver, err := blob.OpenBucket(context.Background(), driverUrl)
 	if err != nil {
 		logrus.Errorf("Cannot construct storage driver: %v", err)
diff --git a/server-go/storage/upload.go b/server-go/storage/upload.go
index 278a7c7e..4d010646 100644
--- a/server-go/storage/upload.go
+++ b/server-go/storage/upload.go
@@ -20,7 +20,6 @@ func (s *Service) UploadFile(inputStream io.ReadCloser, version *UploadedVersion
 	}
 
 	middlewares := nestedStreamMiddlewares{
-		// todo: add a middleware to abort file upload if filesize reached the limit
 		s.createNonEmptyMiddleware(),
 		s.createGPGStreamMiddleware(),
 	}