Guoty worked on backend reliability and code maintainability across two repositories, sleepcoo/sglang and tenstorrent/vllm, over a two-month period. In sleepcoo/sglang, Guoty addressed server startup failures by implementing a robust port allocation strategy in Python, applying defensive programming and boundary checks to prevent port number overflow and ensure stable service initialization. For tenstorrent/vllm, Guoty improved the benchmark_moe.py script by correcting type hints and removing unused imports, enhancing code clarity and maintainability without altering user-facing behavior. The work demonstrated careful attention to error handling, static analysis readiness, and long-term maintainability, leveraging skills in backend development and system programming.