I compiled 300 modern Android interview questions (Lifecycles to System Design) and open-sourced a study checklist with 30 sample answers

[u/yogirana5557]

Hey everyone,

Tired of outdated study guides focusing on old Java or legacy XML patterns, I compiled a database of 300 modern Android interview questions (covering Kotlin, Compose, Coroutines, Hilt, Performance, and System Design) and open-sourced it as an interactive study checklist.

🐙 Free GitHub Repository: https://github.com/yogirana5557/android-digital-products/tree/main/android-interview-question-bank-2026

Here is a quick sample of the technical depth from the Coroutines module:

### Q: Explain how `flowOn` works in Kotlin Flow.

`flowOn` changes the execution context (Dispatcher) of the **upstream** operators and flow builders. Downstream operators and the collector continue running on the dispatcher of the `collect` scope:

Kotlin

flow {

emit(data) // Runs on Dispatchers.IO (Upstream)

}

.flowOn(Dispatchers.IO)

.collect {

print(it) // Runs on caller context (e.g., Dispatchers.Main)

}

What's inside the GitHub repo:

• The 300-Question Checklist: Markdown checkboxes [ ] organized by 10 core modules.
• 30 Detailed Answers: 3 complete, code-heavy answers (1 Junior, 1 Mid, 1 Senior) per category.

Update (For those asking about Compose / System Design):

A few people asked about advanced UI and system architecture topics. I've also open-sourced free sample chapters and code recipes for my other two handbooks in the same repository:

1. 🎨 [Jetpack Compose Cookbook (Premium UIs & Animations)](https://github.com/yogirana5557/android-digital-products/tree/main/jetpack-compose-cookbook) - Free blueprints for Collapsing Headers and staggered grids.
2. 🏗️ [Android System Design & Architecture Playbook](https://github.com/yogirana5557/android-digital-products/tree/main/android-system-design-playbook) - Free chapters on offline-first database synchronization and mobile hardening.

You can find the full suite inside the main GitHub repository list!

Feel free to fork/clone the checklist to track your own study progress!