During October 2025, Donghao Zhang focused on improving the correctness and reliability of RotaryEmbedding within the JustinTong0323/sglang repository. He addressed a subtle bug in the FP32 computation path, refining the logic for applying cached cosine and sine values to ensure accurate results across diverse GPU hardware. By leveraging his expertise in Deep Learning, GPU Computing, and PyTorch, Donghao’s targeted fix reduced numerical errors in production models and enhanced cross-platform stability. His work not only maintained model accuracy but also simplified future maintenance, as he thoroughly documented the changes to support robust deployments and ongoing development within the codebase.