Yifan worked on the deepspeedai/DeepSpeed repository, focusing on resolving a build error related to async IO operations for Huawei Ascend NPU support. By identifying missing source files and aligning the codebase with the NPU architecture, Yifan expanded the Async IO op builder to ensure cross-architecture compatibility and proper symbol resolution. The work involved C++ development, NPU programming, and integration with PyTorch, addressing both build system adjustments and runtime validation. Yifan also documented the environment setup and error resolution steps, contributing to reproducibility and maintainability. This targeted bug fix improved DeepSpeed’s reliability on Ascend NPUs and supported future enhancements.