ProGuard is a bytecode optimizer / shrinker and obfuscator that is also part of the Android build tools to minimize Android applications as much as possible.

I have been the product lead and lead developer of this project (and its commercial sibling DexGuard) for several years.

Some of the notable personal contributions to the project:

• Support for backporting Java 8 language features and API calls
• Parallelization of optimization step
• Gradle plugin
• Many bugfixes and small improvements

ProGuard is an amazing piece of software, difficult to master but once you get used to it, everything feels natural.