Worked on stabilizing keyword argument handling in the facebook/pyrefly library to ensure seamless integration with PyInfra and improve developer ergonomics. Addressed a type conversion issue where keyword arguments were incorrectly treated as positional-only, implementing a fix using Python’s ParamSpec and to_subset_param to preserve correct argument types during type checking. Enhanced error handling and type checking, and added comprehensive tests to validate the solution across mypy and PyInfra workflows. Focused on maintaining compatibility and preventing regression in downstream projects, demonstrating proficiency in Python, Rust, and library development while ensuring robust static and dynamic validation for reliable code quality.