Worked on enhancing Pyre-check’s reliability by developing a comprehensive suite of tests targeting type checking behavior for Python’s try, except, else, and finally constructs. Focused on validating existing semantics and ensuring that future changes would not introduce regressions, the work involved careful analysis of type checking logic and integration with the project’s established code review process. Leveraged OCaml for both test implementation and type system validation, emphasizing robust testing practices and infrastructure improvements. This contribution to the facebook/pyre-check repository strengthened the foundation for ongoing evolution of type checking features, supporting maintainability and stability in a complex, evolving codebase.