How to protect apk from reverse engineering

I will explain to day..hide apk file when Reverse engineering...

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: Use ProGuard to obfuscate application code.

Steps:

When we develop an Application build.gradle  plays very important role,so if you want protect your code from hackers this is very helpful for  you.

 release {
   shrinkResources true

   minifyEnabled true 

   proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'

}

Now sync your project one mapping file generated as shown below:

Now,generate signed APK file Upload to play store. After do this upload the mapping.txt file. 

Select Android vital-> go to Deobfuscation and upload above metioned file

It's done...