Learning from the expert for handling shift left and app performance improvement for mobile applications. Recently, mobile applications have had more complexity than backend applications. To tackle such complexity, I present an experience from the mobile expert to address issues around app performance.

1. Shift Left
Beyond
App Performance
Improvement at Gojek
1

2. Hai i’m Raditya Gumay
Principal Engineer at Gojek
● Performance
● Framework and Tools
● Standardization and Guidelines

3. lets get a ride!

4. Shift Left
App
Performance

5. Shift Left

6. Y
X Time

8. Users receive In-app updates

9. Users experiencing an issue

10. As an engineer you realize
the issue

12. Branch by abstraction could help!

13. Y
X Time

14. Y
X Time

15. How do we built App Preventive

19. App Launch

20. App Launch
1.Load and launch the app
2.Display a starting/preview window
3.Create the app proces
4.Create the app object
5.Launch the main thread
6.Create the entry point activity
7.Inflate view
8.Lay out the screen
9.Perform initial draw

23. App Launch
:start-time class StartTimeContentProvider : ContentProvider() {
override fun onCreate(): Boolean {
return true
}
companion object {
val startTime = SystemClock.uptimeMillis()
}
}

24. App Launch
:start-time class StartTimeContentProvider : ContentProvider() {
override fun onCreate(): Boolean {
return true
}
companion object {
val startTime = SystemClock.uptimeMillis()
}
}

25. Class Loaded vs Class Initialized

26. App Launch
:start-time class FirstDrawListener private constructor(
private val view: View,
private val onFirstDrawCallback: OnFirstDrawCallback
) : ViewTreeObserver.OnDrawListener {
...
}

27. App Launch
:start-time class FirstDrawListener private constructor(
private val view: View,
private val onFirstDrawCallback: OnFirstDrawCallback
) : ViewTreeObserver.OnDrawListener {
override fun onDraw() { }
}

28. App Launch
:start-time class FirstDrawListener private constructor(
private val view: View,
private val onFirstDrawCallback: OnFirstDrawCallback
) : ViewTreeObserver.OnDrawListener {
init {
registerFirstDrawListener()
}
override fun onDraw() { }
}

29. App Launch
:start-time
class FirstDrawListener private constructor(
private val view: View,
private val onFirstDrawCallback: OnFirstDrawCallback
) : ViewTreeObserver.OnDrawListener {
init {
registerFirstDrawListener()
}
override fun onDraw() { }
private fun registerFirstDrawListener() {
if (view.viewTreeObserver.isAlive && view.isAttachedToWindow) {
view.viewTreeObserver.addOnDrawListener(this@FirstDrawListener)
} else {
view.addOnAttachStateChangeListener(object : View.OnAttachStateChangeListener {
override fun onViewAttachedToWindow(v: View?) {
if (view.viewTreeObserver.isAlive) {
view.viewTreeObserver.addOnDrawListener(this@FirstDrawListener)
}
view.removeOnAttachStateChangeListener(this)
}
override fun onViewDetachedFromWindow(v: View?) {
/*NoOp*/
}
})
}
}
}

30. App Launch
:start-time
class FirstDrawListener private constructor(
private val view: View,
private val onFirstDrawCallback: OnFirstDrawCallback
) : ViewTreeObserver.OnDrawListener {
init {
registerFirstDrawListener()
}
override fun onDraw() {
if (!onDrawInvoked) {
onDrawInvoked = true
onFirstDrawCallback.onDrawingStart()
...
}
}
private fun registerFirstDrawListener() {
...
}
}

31. App Launch
:start-time
FirstDrawListener.registerFirstDrawListener(view, object : FirstDrawListener.OnFirstDrawCallback {
override fun onDrawingStart() {
val startTIme = StartTimeContentProvider.startTime
val endTime = SystemClock.uptimeMillis()
val result = endTime - startTime
println("$TAG App took $result ms to launch")
}
override fun onDrawingFinish() {
...
}
})

32. App Launch
:start-time
FirstDrawListener.registerFirstDrawListener(view, object : FirstDrawListener.OnFirstDrawCallback {
override fun onDrawingStart() {
val startTIme = StartTimeContentProvider.startTime
val endTime = SystemClock.uptimeMillis()
val result = endTime - startTime
println("AppStartup took $result ms to launch")
}
override fun onDrawingFinish() {
...
}
})

33. App Launch
:start-time log=$(grep -m1 "AppStartup took " logcat)
XYZ
XYZ
XYZ
XYZ
XYZ
XYZ

34. App Size
XYZ XYZ

36. App Improvement

37. App Size
- Download Size
- Install Size
App Startup
- Cold Start
- Hot and Warm
are excellent!
UI Hangs
- Frozen Frames
- Slow UI
Rendering
- Screen Loading

38. App Size

39. App Bundle, meh
Proguard Rules
Assets Size
Reduction
Assets
OTA
Resources
OTA

40. Proguard
Rules
- Scanning the merged rules, see if there any
misconfiguration rules

41. Proguard
Rules
- Scanning the merged rules, see if there any
misconfiguration rules (check the consumer-
pro.rules!)

42. Proguard
Rules
- Scanning the merged rules, see if there any
misconfiguration rules (check the consumer-
pro.rules!)
- Let proguard playground help you!

43. Proguard
Rules
https://playground.proguard.com/

44. Proguard
Rules
- Scanning the merged rules, see if there any
misconfiguration rules (check the consumer-
pro.rules!)
- Let proguard playground help you!
- Check the dex files method number!

45. Proguard
Rules

46. App Bundle, meh
Proguard Rules
Assets Size
Reduction
Assets
OTA
Resources
OTA

47. App Size Take away

48. App Size Take Away
- Check the proguard rules
- OTA everything that you can do
- Optimize assets
- Applied branch by abstraction where you can
hardcoded the features!
- App Bundle is requirement!
- Dynamic Feature Modules!

49. App Startup

50. Traces Point
Traces Graph
Perfetto
Base
Profiler
Systrace

59. App Startup Take away

60. App Startup Take Away
- Do not blocking main-thread!
- Parallelise the tasks!
- Lazy initialization instead of eager initialization
- Watch out the class load time!
- Watch out multiple instance!
- Watch out CPU and Memory Pressure!
- Watch out multiple activity starts!

61. ↓30%
Average
App Startup Achievement
↓29.2%
95th
Percentile

62. ↓27%
App size reduction
App Size Achievement
↓25.6%
App size reduction

63. UI Janks Achievement
↓6.96%
95th
Percentile

64. Don’t try to find the best
design in software
architecture; instead, strive for
the least worst combination of
trade-offs
- Neal Ford (Software Architecture: The hard Part)