Key Takeaways 1-Don’t trust the device — design your app assuming the environment is hostile. 2- Secure early — architecture & decisions made before coding matter the most. 3- Use platform security — Keystore, integrity checks, and server-side validation. 4- Protect app components — validate intents, deep links, and exposed surfaces. 5- Enable runtime defense — detect root, hooking, overlays, and abuse signals.