Most Android devs stop at UI or using Jetpack libraries. The real learning begins when you explore what happens under the hood.
Start exploring these:
- Why does an Android app lag?: Smooth 60fps UI, Choreographer, GC, Recomposition
- LRUCache and Bitmap Pool
- ViewModel Internals
- Android Runtime: ART, AOT, JIT
- Coroutines Internals
- OkHttp internals, like connection pooling
Pick one topic, explore it in depth for 1–2 weeks, and master it.