Worked on enhancing error handling and input validation within the RLlib component of the ray-project/ray repository. Focused on backend development using Python, the work involved replacing tuple-style ValueError messages with more descriptive string messages to improve clarity for both developers and users. Added comprehensive regression tests to cover multiple scenarios, including the offline dataset writer, filter error handling, and space serialization helpers. This approach improved robustness, maintainability, and the overall debugging experience. Emphasized error handling and unit testing to ensure that new error reporting mechanisms functioned as intended, resulting in clearer user-facing messages and streamlined issue triage.