diff --git a/backend/cmd/db/main.go b/backend/cmd/db/main.go
index 564fcbab5..8236586c2 100644
--- a/backend/cmd/db/main.go
+++ b/backend/cmd/db/main.go
@@ -7,7 +7,6 @@ import (
 	"openreplay/backend/internal/datasaver"
 	"openreplay/backend/internal/handlers"
 	"openreplay/backend/internal/handlers/custom"
-	"openreplay/backend/pkg/intervals"
 	"time"
 
 	"os"
@@ -33,9 +32,9 @@ func main() {
 
 	// Declare message handlers we want to apply for each incoming message
 	msgHandlers := []handlers.MessageProcessor{
-		custom.NewMainHandler(),
-		custom.NewInputEventBuilder(),
-		custom.NewPageEventBuilder(),
+		custom.NewMainHandler(), // TODO: separate to several handler
+		//custom.NewInputEventBuilder(),
+		//custom.NewPageEventBuilder(),
 	}
 
 	// Create handler's aggregator
@@ -54,7 +53,6 @@ func main() {
 			if !postgres.IsPkeyViolation(err) {
 				log.Printf("Message Insertion Error %v, SessionID: %v, Message: %v", err, sessionID, msg)
 			}
-			// TODO: can we lose data here because of db error?
 			return
 		}
 
@@ -95,7 +93,7 @@ func main() {
 	consumer := queue.NewMessageConsumer(
 		cfg.GroupDB,
 		[]string{
-			cfg.TopicRawWeb, // TODO: is it necessary or not?
+			cfg.TopicRawWeb,
 			cfg.TopicRawIOS,
 			cfg.TopicTrigger, // to receive SessionEnd events
 		},
@@ -109,7 +107,6 @@ func main() {
 	signal.Notify(sigchan, syscall.SIGINT, syscall.SIGTERM)
 
 	commitTick := time.Tick(cfg.CommitBatchTimeout)
-	checkTick := time.Tick(intervals.EVENTS_COMMIT_INTERVAL * time.Millisecond)
 	for {
 		select {
 		case sig := <-sigchan:
@@ -118,12 +115,14 @@ func main() {
 			os.Exit(0)
 		case <-commitTick:
 			pg.CommitBatches()
+			// TODO: ee commit stats !!!
+			//if err := commitStats(); err != nil {
+			//	log.Printf("Error on stats commit: %v", err)
+			//}
 			// TODO?: separate stats & regular messages
 			if err := consumer.Commit(); err != nil {
 				log.Printf("Error on consumer commit: %v", err)
 			}
-		case <-checkTick:
-			// checkTimeout
 		default:
 			err := consumer.ConsumeNext()
 			if err != nil {
diff --git a/backend/cmd/heuristics/main.go b/backend/cmd/heuristics/main.go
index ddfd29095..9c77cb4ba 100644
--- a/backend/cmd/heuristics/main.go
+++ b/backend/cmd/heuristics/main.go
@@ -78,7 +78,7 @@ func main() {
 			consumer.Close()
 			os.Exit(0)
 		case <-tick:
-			builderMap.IterateReadyMessages(time.Now().UnixMilli(), func(sessionID uint64, readyMsg messages.Message) {
+			builderMap.IterateReadyMessages(func(sessionID uint64, readyMsg messages.Message) {
 				producer.Produce(cfg.TopicTrigger, sessionID, messages.Encode(readyMsg))
 			})
 			producer.Flush(cfg.ProducerTimeout)
diff --git a/backend/internal/builder/builder.go b/backend/internal/builder/builder.go
index a00ad194a..4916764cd 100644
--- a/backend/internal/builder/builder.go
+++ b/backend/internal/builder/builder.go
@@ -2,7 +2,6 @@ package builder
 
 import (
 	"openreplay/backend/internal/handlers"
-	"openreplay/backend/pkg/intervals"
 	. "openreplay/backend/pkg/messages"
 )
 
@@ -26,6 +25,15 @@ func (b *builder) iterateReadyMessage(iter func(msg Message)) {
 	b.readyMsgs = nil
 }
 
+func (b *builder) checkSessionEnd(message Message) {
+	if _, isEnd := message.(*IOSSessionEnd); isEnd {
+		b.ended = true
+	}
+	if _, isEnd := message.(*SessionEnd); isEnd {
+		b.ended = true
+	}
+}
+
 func (b *builder) handleMessage(message Message, messageID uint64) {
 	timestamp := GetTimestamp(message)
 	if b.timestamp < timestamp {
@@ -36,42 +44,10 @@ func (b *builder) handleMessage(message Message, messageID uint64) {
 		return
 	}
 
-	if _, isEnd := message.(*IOSSessionEnd); isEnd {
-		b.ended = true
-	}
-	if _, isEnd := message.(*SessionEnd); isEnd {
-		b.ended = true
-	}
-
+	b.checkSessionEnd(message)
 	for _, p := range b.processors {
-		/* If nil is not returned explicitely by Handle, but as the typed nil
-		("var i *IssueEvent; return i;")
-		The `rm != nil` will be true.
-		TODO: enforce nil to be nil(?) or add `isNil() bool` to the Message types
-			because this part is expected to be etendable by user with custom messageProcessor's.
-			Use of reflrction will be probably bad on millions of messages?
-		*/
 		if rm := p.Handle(message, messageID, b.timestamp); rm != nil {
 			b.readyMsgs = append(b.readyMsgs, rm)
 		}
 	}
 }
-
-func (b *builder) checkTimeouts(ts int64) bool {
-	if b.timestamp == 0 {
-		return false // SessionStart happened only
-	}
-
-	lastTsGap := ts - int64(b.timestamp)
-	// Maybe listen for `trigger` and react on SessionEnd instead (less reliable)
-	if lastTsGap > intervals.EVENTS_SESSION_END_TIMEOUT {
-		for _, p := range b.processors {
-			// TODO: same as above
-			if rm := p.Build(); rm != nil {
-				b.readyMsgs = append(b.readyMsgs, rm)
-			}
-		}
-		return true
-	}
-	return false
-}
diff --git a/backend/internal/builder/builderMap.go b/backend/internal/builder/builderMap.go
index 6b2c22bec..b393bcd28 100644
--- a/backend/internal/builder/builderMap.go
+++ b/backend/internal/builder/builderMap.go
@@ -31,13 +31,19 @@ func (m *builderMap) HandleMessage(sessionID uint64, msg Message, messageID uint
 	b.handleMessage(msg, messageID)
 }
 
-func (m *builderMap) IterateReadyMessages(operatingTs int64, iter func(sessionID uint64, msg Message)) {
+func (m *builderMap) IterateReadyMessages(iter func(sessionID uint64, msg Message)) {
 	for sessionID, b := range m.sessions {
-		sessionEnded := b.checkTimeouts(operatingTs)
+		if b.ended {
+			for _, p := range b.processors {
+				if rm := p.Build(); rm != nil {
+					b.readyMsgs = append(b.readyMsgs, rm)
+				}
+			}
+		}
 		b.iterateReadyMessage(func(msg Message) {
 			iter(sessionID, msg)
 		})
-		if sessionEnded {
+		if b.ended {
 			delete(m.sessions, sessionID)
 		}
 	}
diff --git a/backend/internal/handlers/custom/mainHandler.go b/backend/internal/handlers/custom/mainHandler.go
index 7e653c250..52a6278c0 100644
--- a/backend/internal/handlers/custom/mainHandler.go
+++ b/backend/internal/handlers/custom/mainHandler.go
@@ -125,9 +125,6 @@ func (b *builder) Handle(message Message, messageID uint64, timestamp uint64) Me
 			b.buildInputEvent()
 			b.ieBuilder.ClearLabels()
 			b.peBuilder.HandleSetPageLocation(msg, messageID, b.timestamp)
-			// TODO: what to do with this code?
-			//b.miFinder.HandleSetPageLocation(msg)
-			//b.ciFinder.HandleSetPageLocation(msg)
 		}
 	case *PageLoadTiming:
 		if rm := b.peBuilder.HandlePageLoadTiming(msg); rm != nil {
@@ -137,17 +134,6 @@ func (b *builder) Handle(message Message, messageID uint64, timestamp uint64) Me
 		if rm := b.peBuilder.HandlePageRenderTiming(msg); rm != nil {
 			b.appendReadyMessage(rm)
 		}
-	case *PerformanceTrack:
-		// TODO: what to do with this code?
-		//if rm := b.ptaBuilder.HandlePerformanceTrack(msg, b.timestamp); rm != nil {
-		//	b.appendReadyMessage(rm)
-		//}
-		//if rm := b.ciFinder.HandlePerformanceTrack(msg, messageID, b.timestamp); rm != nil {
-		//	b.appendReadyMessage(rm)
-		//}
-		//if rm := b.miFinder.HandlePerformanceTrack(msg, messageID, b.timestamp); rm != nil {
-		//	b.appendReadyMessage(rm)
-		//}
 	case *SetInputTarget:
 		if rm := b.ieBuilder.HandleSetInputTarget(msg); rm != nil {
 			b.appendReadyMessage(rm)
@@ -158,10 +144,6 @@ func (b *builder) Handle(message Message, messageID uint64, timestamp uint64) Me
 		}
 	case *MouseClick:
 		b.buildInputEvent()
-		// TODO: what to do with this code?
-		//if rm := b.crDetector.HandleMouseClick(msg, messageID, b.timestamp); rm != nil {
-		//	b.appendReadyMessage(rm)
-		//}
 		if msg.Label != "" {
 			b.appendReadyMessage(&ClickEvent{
 				MessageID:      messageID,
@@ -256,20 +238,7 @@ func (b *builder) Handle(message Message, messageID uint64, timestamp uint64) Me
 			Timestamp: b.timestamp,
 			Type:      msg.Type,
 		})
-		// TODO: what to do with this code?
-		//case *CreateElementNode, *CreateTextNode:
-		//	b.ddDetector.HandleNodeCreation()
-		//case *RemoveNode:
-		//	b.ddDetector.HandleNodeRemoval(b.timestamp)
-		//case *CreateDocument:
-		//	if rm := b.ddDetector.Build(); rm != nil {
-		//		b.appendReadyMessage(rm)
-		//	}
 	}
-	// TODO: what to do with this code?
-	//if rm := b.dcDetector.HandleMessage(message, messageID, b.timestamp); rm != nil {
-	//	b.appendReadyMessage(rm)
-	//}
 	return nil
 }
 
diff --git a/backend/internal/handlers/ios/appNotResponding.go b/backend/internal/handlers/ios/appNotResponding.go
index 097361c00..b5f6cd2f0 100644
--- a/backend/internal/handlers/ios/appNotResponding.go
+++ b/backend/internal/handlers/ios/appNotResponding.go
@@ -3,7 +3,6 @@ package ios
 import (
 	"openreplay/backend/internal/handlers"
 	. "openreplay/backend/pkg/messages"
-	"time"
 )
 
 /*
@@ -22,9 +21,11 @@ type AppNotResponding struct {
 	lastLabel              string
 	lastHeartbeatTimestamp uint64
 	lastHeartbeatIndex     uint64
+	lastTimestamp          uint64
 }
 
 func (h *AppNotResponding) Handle(message Message, messageID uint64, timestamp uint64) Message {
+	h.lastTimestamp = timestamp
 	var event Message = nil
 	switch m := message.(type) {
 	case *IOSClickEvent:
@@ -48,7 +49,7 @@ func (h *AppNotResponding) Handle(message Message, messageID uint64, timestamp u
 }
 
 func (h *AppNotResponding) Build() Message {
-	return h.build(uint64(time.Now().Unix()))
+	return h.build(h.lastTimestamp)
 }
 
 func (h *AppNotResponding) build(timestamp uint64) Message {
diff --git a/backend/internal/handlers/ios/performanceAggregator.go b/backend/internal/handlers/ios/performanceAggregator.go
index b4bc812c7..2a9401748 100644
--- a/backend/internal/handlers/ios/performanceAggregator.go
+++ b/backend/internal/handlers/ios/performanceAggregator.go
@@ -3,7 +3,6 @@ package ios
 import (
 	"openreplay/backend/internal/handlers"
 	. "openreplay/backend/pkg/messages"
-	"time"
 )
 
 /*
@@ -29,14 +28,16 @@ func (va *valueAggregator) aggregate() uint64 {
 
 type PerformanceAggregator struct {
 	handlers.ReadyMessageStore
-	pa      *IOSPerformanceAggregated
-	fps     valueAggregator
-	cpu     valueAggregator
-	memory  valueAggregator
-	battery valueAggregator
+	pa            *IOSPerformanceAggregated
+	fps           valueAggregator
+	cpu           valueAggregator
+	memory        valueAggregator
+	battery       valueAggregator
+	lastTimestamp uint64
 }
 
 func (h *PerformanceAggregator) Handle(message Message, messageID uint64, timestamp uint64) Message {
+	h.lastTimestamp = timestamp
 	if h.pa == nil {
 		h.pa = &IOSPerformanceAggregated{} // TODO: struct type in messages
 	}
@@ -94,7 +95,7 @@ func (h *PerformanceAggregator) Handle(message Message, messageID uint64, timest
 }
 
 func (h *PerformanceAggregator) Build() Message {
-	return h.build(uint64(time.Now().Unix()))
+	return h.build(h.lastTimestamp)
 }
 
 func (h *PerformanceAggregator) build(timestamp uint64) Message {