During April 2026, Daniel Leong enhanced parameter specification handling in the facebook/pyrefly repository, focusing on preserving richer metadata such as parameter names and types rather than reducing them to type information alone. He introduced a new structure to distinguish positional-only from positional arguments, improving the robustness of function argument processing. The work involved updating core logic and associated tests for compatibility with these changes, as well as addressing a related issue in the codebase. Leveraging Python and Rust, Daniel strengthened test coverage and documentation, laying the groundwork for safer refactoring and enabling more precise parameter-name-based analyses in future development.