Inside an APK — Android Reverse Engineering Basics
Welcome to the first video in my Android Reverse Engineering Basics playlist! In this episode, we’ll explore how Android apps are built, compiled, and packaged — and what’s actually inside an APK file.
I’ll cover the full lifecycle of an Android app: from Java/Kotlin code, to bytecode, to DEX, and finally to APK/AAB packaging. We’ll then dive into the structure of an APK — including the Manifest, DEX files, Smali, resources, assets, native libraries, and signatures.
What you’ll learn
How Android apps are compiled (Java/Kotlin → class → DEX).
The difference between DVM (Dalvik) and ART (Android Runtime).
What’s inside an APK (Android Package) vs an AAB (App Bundle).
APK structure: Manifest, classes.dex, res/, assets/, lib/, META-INF/.
What Smali is and why it matters in reverse engineering.
Basics of resources and assets for reverse engineers.
Why APK signing and verification is important.
Chapters / Timestamps
0: 00 — Intro & channel welcome
0: 25 — Writing Android apps (Java/Kotlin, Android Studio)
0: 38 — Compilation to bytecode (.class files)
1: 06 — Conversion to DEX (Dalvik Executable)
1: 45 — Packaging into APK & AAB (differences explained)
3: 16 — APK structure overview (Manifest, DEX, res/, assets/, lib/, META-INF/)
4: 02 — AndroidManifest.xml explained
4: 38 — DEX deep dive & multiple DEX files
5: 16 — Smali basics & example code
6: 40 — Resources (res/) folder
7: 00 — Assets/ folder
7: 26 — Native libraries (lib/) and their role
7: 57 — META-INF & APK signatures
8: 15 — Wrap-up & conclusion
This video is for educational purposes only and aimed at developers, researchers, and anyone interested in learning how Android apps work under the hood.
This is Part 1 of my Android Reverse Engineering Basics playlist. Subscribe so you don’t miss Part 2, where we’ll dive into JADX.
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#android #reverseengineering #apk #androidsecurity #smali