How to avoid reverse engineering of an APK file?

Question

I am developing a payment processing app for Android, and I want to prevent a hacker from accessing any resources, assets or source code from the APK file.<

Answer 1

100% avoidance of reverse engineering of the Android APK is not possible, but you can use these ways to avoid extracting more data, like source code, assets form your APK, and resources:

1. Use ProGuard to obfuscate application code

2. Use NDK using C and C++ to put your application core and secure part of code in .so files

3. To secure resources, don't include all important resources in the assets folder with APK. Download these resources at the time of application first start up.