Worked on the facebook/buck2 repository to enhance the source parser by enabling the collection of comment spans during BUILD file parsing. This feature allowed for comment-aware processing, such as merging BUILD.in comments into generated BUILD files, while maintaining full API stability and avoiding any public interface changes. The approach involved extending the Starlark parser in Rust, focusing on safe code parsing techniques and ensuring seamless integration with existing workflows. Collaboration was demonstrated through linked pull requests and code reviews, supporting cross-repository consistency. The work improved automation and consistency in BUILD file integration, leveraging skills in Rust, code parsing, and software development.