Over two months, contributed to facebook/lexical and facebook/pyrefly by delivering stability fixes, UX enhancements, and improved error handling. Addressed editor crashes in lexical when importing malformed <details> elements, adding targeted tests and strengthening TypeScript type safety and documentation. Enhanced the pyrefly sandbox by centering error lines for better user context and expanded backend reliability through Rust-based bug fixes. Improved Python type checking in pyrefly by refining error reporting for method parameter defaults and NamedTuple edge cases, using metadata-driven validation. Work emphasized robust testing, JSON serialization, and clear developer guidance, resulting in more reliable, maintainable code across both repositories.