How do you improve the performance of an Android app?

Measure first with Android Studio Profiler for CPU, memory, and network; Macrobenchmark for startup and scrolling; and Play Console vitals for real-world ANR and crash rates on real devices, which is what actually matters.

Startup time:

• Do as little as possible in Application.onCreate. Third-party SDK initialisation is the usual culprit — use App Startup or lazy initialisation.
• Avoid disk and network on the startup path.
• Baseline Profiles ship ahead-of-time compilation hints and give a substantial, low-effort improvement to startup and scrolling.

Rendering and jank:

• Keep the main thread free — no I/O, no heavy parsing.
• Flatten deep view hierarchies; use ConstraintLayout, or Compose with stable parameters to limit recomposition.
• Use paging for long lists rather than loading everything.

Memory:

• Fix leaks with LeakCanary — retained Activities are the most common.
• Load images at display size with Coil or Glide rather than full resolution bitmaps, which is the single largest source of out-of-memory crashes.

App size: enable R8 shrinking and obfuscation, ship an Android App Bundle so users download only what their device needs, use WebP or vector drawables, and audit dependencies.

Note: Test on a low-end device. An app that feels fine on a flagship can be unusable on the hardware much of the market actually uses.