Xiafeng Li focused on backend reliability engineering for the PKUHPC/CraneSched repository, addressing critical issues in task execution and inter-service communication. Over two months, Xiafeng resolved three complex bugs involving C++ environment variable handling and gRPC network stability. By correcting the assignment of the CRANE_PARTITION environment variable, Xiafeng improved task configuration accuracy and reduced runtime errors for default-partition tasks. Additional work included refining the retrieval of environment variables from the task manager and enhancing gRPC client connectivity through keepalive channel arguments. Xiafeng’s contributions deepened the system’s robustness, prioritizing correctness and stability over new features, and demonstrated strong backend and network programming skills.