Worked on enhancing the ruby/prism repository by improving the robustness and correctness of the parser, specifically in handling lambda argument parsing. Focused on addressing edge cases involving splat and keyword splat arguments, the work introduced error checks to prevent invalid syntax and refactored the parameter parsing logic to better support multi-line labelled lambda arguments. This involved updating the parser state and introducing new parameters to manage block context, resulting in more stable parsing behavior. Utilized C for parser development, applying skills in compiler construction and syntax analysis to expand test coverage and reduce syntax-related failures in continuous integration workflows.