🗺️ 04 · learn android
Android Developer Roadmap
The dependency-ordered map
Nine stages, each a prerequisite for the next — the order is the content.
Most roadmaps for Android are a flat list of keywords: Kotlin, Compose, Coroutines, Room, Retrofit, MVVM. A flat list hides the thing that actually matters — that these topics have an order, and learning them out of order is why most people stall. You can't understand a ViewModel before the Activity lifecycle it survives; you can't understand Coroutines before what a thread is and why blocking the main one is bad.
This roadmap's value is the arrows, not the boxes. Each stage assumes the ones before it, so you're never asked to understand something that builds on a topic you haven't reached yet.
The mental model
How it fits together
The nine stages, in dependency order
stages 1, 5 and 7 map to the runnable repos in this collection
Key concepts
The ideas to internalise
Foundation
Java and Kotlin, and Android Studio — the language and the tool. Everything else is written in and built with these.
Core concepts
Activity, Service, BroadcastReceiver, ContentProvider, Intents, and the Activity lifecycle. How an app is shaped before you draw a pixel.
Concurrency
Threads, then Coroutines, then Flow, then WorkManager. The #1 crash source and the #1 interview topic.
Architecture
MVVM/MVI, dependency injection, Clean Architecture. How code stays maintainable as it scales.
Order beats completeness
A hundred topics in no order produces engineers who know names but not relationships. Treat each stage as a prerequisite.
Learn by building
Each stage maps to a runnable repo — 'learn it' always means 'build and run something', not 'tick a checkbox'.
The nine stages
In dependency order
- 1FoundationJava → Kotlin cheat sheet →
Java, Kotlin, Android Studio — the language and the tool.
- 2Core conceptsHow an app launches →
Components, Intents, and the Activity lifecycle.
- 3User interface
Views, ViewGroups, RecyclerView, Fragments.
- 4Persistence
SharedPreferences, DataStore, Room, files.
- 5Threading & concurrencyCoroutines · Flow →
Threads, then Coroutines, then Flow, then WorkManager.
- 6Networking
OkHttp, Retrofit, JSON, OAuth, status codes.
- 7ArchitectureMVVM sample app →
MVVM / MVI, dependency injection, Clean Architecture.
- 8Testing & quality
Unit and instrumentation tests, debugging, memory.
- 9Advanced & release
Compose, Firebase, security, signing, the Play Store.
The takeaway
Work top-to-bottom and don't skip ahead — stage N is the foundation for stage N+1, and a gap at stage 3 will quietly destabilise you at stage 7. When you hit a wall later, the wall is usually a prerequisite you glossed over, not the current topic.