Filip contributed to the wasp-lang/wasp repository by enhancing authentication user experience and improving build reliability. He developed a configurable authentication UI, allowing distinct button labels for login and signup flows, which clarified user interactions in Waspello. Using React and JavaScript, Filip introduced a submitButtonLabel prop to the EmailAndPassForm component, addressing the need for clearer authentication states. Additionally, he performed dependency management maintenance by purging the package-lock.json file, ensuring deterministic and conflict-free installs. His work focused on frontend development and dependency management, delivering targeted improvements that streamlined release processes and addressed specific usability and reliability challenges within the project’s codebase.