Luis worked on enhancing Java debugging capabilities in the facebook/buck2 and buck2-prelude repositories by implementing Java classmap inheritance for debuggers using prebuilt jars. He introduced a mechanism allowing Java libraries to inherit class-to-source map information from source-compiled dependencies, addressing issues with missing class entries during debugging when prebuilt artifacts were involved. This required careful integration with the Buck2 build system and a debuginfo merge strategy to ensure reliable classmap propagation across multi-target builds. Using Java and Python, Luis focused on maintainable code changes that improved reliability and cross-repository collaboration, demonstrating depth in build systems and debugging workflows.