There are many ways to contribute to the DataPrep project:
Submit bugs and help us verify the fixes as they are checked in
Contribute bug fixes
Review the source code changes
Engage with other DataPrep users and developers on StackOverflow
Help each other in the DataPrep Community Discord and Mail list & Forum
Follow us on Twitter
Provide use cases and write down your user experience
Checkout the DataPrep wiki page for development documentations.