Worked on the facebook/buck2-prelude repository to address a type inconsistency in the test_binary module, focusing on improving the reliability of the Buck2 build system. The contribution involved updating the listing_to_testnames function to return a list of binaries instead of strings, thereby enforcing stricter type contracts throughout the test suite. This change reduced the risk of runtime errors and continuous integration failures, supporting ongoing efforts toward type safety and maintainability. Leveraged Erlang development and testing skills to ensure the test framework adhered to correct specifications, ultimately enhancing the stability and robustness of automated testing within the Buck2 ecosystem.