Arne contributed to the localstack/moto repository by addressing a bug in SSM parameter tag filtering, ensuring that the describe_parameters operation accurately reflected tag additions, updates, and removals. Using Python and leveraging backend development and cloud services mocking skills, Arne expanded the test suite to cover multiple tag scenarios, which improved reliability and prevented future regressions. The work focused on enhancing the correctness of parameter discovery and tag-based access control without impacting performance. Through targeted testing and careful code changes, Arne delivered a robust fix that increased confidence in the system’s behavior for customers relying on precise tag filtering in cloud environments.