During December 2025, Andrey Khmylov enhanced the facebook/pyre-check repository by developing a comprehensive suite of tests targeting type checking behavior for Python’s try, except, else, and finally constructs. Using OCaml, he focused on validating and documenting the current semantics, ensuring that existing try-finally behavior remained stable throughout the process. His approach emphasized robust test coverage and alignment with the established code review workflow, supporting future evolution of type checking logic. By strengthening the test infrastructure and leveraging his skills in OCaml and testing, Andrey enabled the team to confidently maintain and extend Pyre-check’s type system with greater reliability.