Worked on stability and correctness improvements in the CPython ecosystem, focusing on backend development and debugging using C and Python. In the picnixz/cpython repository, addressed email serialization issues by updating the encoding path to support iso-2022-jp, ensuring payloads are properly encoded and preventing UnicodeEncodeErrors. Enhanced the content manager and expanded test coverage to validate these changes. In python/cpython, improved memory management by adding a NULL check in the context variable setting function, preventing crashes during allocation failures. These targeted bug fixes reduced user-facing errors, increased runtime resilience, and contributed to more robust and reliable core API behavior.