Performance Issues

1. Crashes

The app face-plants and disappears. Users love this.

• Common causes

  • NullPointerException worship

  • Index out of bounds

  • Bad lifecycle handling

  • Native crashes (C/C++)

2. ANR (Application Not Responding)

• Why it happens

  • Blocking the main thread for ~5 seconds (UI)

  • Doing I/O, network, or heavy computation on main

  • Synchronized locks that never come back with milk

• Common Causes

  • Disk reads in onCreate()

  • Long loops in click handlers

  • Waiting on background threads from UI

3. Memory Leaks

• Causes

  • Static references to Context

  • Long-lived objects holding Views/Activities

  • Listeners not unregistered

  • Coroutines / threads that outlive the screen

• Impact

  • Gradual memory growth

  • Eventually leads to OOM and crashes