Part II — Android platform and build system

What this part teaches

An Android app is not just Kotlin code. The operating system starts processes, creates components, delivers IPC calls, manages memory, recreates UI, resolves resources, and installs an optimized APK or App Bundle produced by Gradle and Android build tools.

Pages

Chapter 1 — How Android works

1. Android architecture: the big picture
2. Framework APIs and system services
3. Linux processes, UIDs, and the app sandbox
4. Execution trace: posting a notification

Remaining Part II chapters

5. Processes, app startup, and process death
   • Zygote and process creation
   • Startup performance: TTID and TTFD
   • Process death and state restoration
6. ART, DEX, and runtime execution
   • Interpreter, JIT, AOT, and profiles
   • Heap, garbage collection, and leaks
   • Baseline and Startup Profiles
   • Runtime interview scenarios
7. Binder and Android IPC — deep chapter
   • Proxy, Stub, Parcel, and call path
   • Practical AIDL client and server
   • Threading, reentrancy, and deadlocks
   • Failures, limits, identity, and security
   • Interview questions and exercises
8. Application components and lifecycle
9. Activities, tasks, launch modes, and back stack
10. Fragments and view lifecycle
    • Intents, filters, results, and secure messaging
    • Context types and lifetime ownership
    • Component interview scenarios
11. Resources, configuration, and compatibility
    • Density, dp, sp, pixels, and graphics
    • Configuration changes and state
    • Localization, plurals, formatting, and RTL
    • Manifest merging and API/device compatibility
    • Interview scenarios
12. Gradle, AGP, variants, R8, and build performance
    • Gradle lifecycle, tasks, Providers, and caches
    • AGP build types, flavors, variants, and source sets
    • Dependencies, API exposure, and catalogs
    • R8, keep rules, shrinking, and retrace
    • Signing, secrets, APK/AAB, and release identity
    • Build performance, CI, and interviews
13. Platform interview scenarios and checklist

:::note Rewrite status Chapter 1 now follows the deep practical format. The remaining Part II pages are working outlines and will be expanded chapter by chapter to the same standard. :::