During November 2025, Chunshuo Qian focused on backend development and algorithm optimization for the IBM/vllm repository, addressing a critical issue in distributed computing. He identified and fixed a bug in the calculation of sequence length distribution for distributed training, specifically correcting the dcp_local_seq_lens logic. This Python-based solution ensured accurate per-node sequencing, which improved multi-node model performance and system stability. By refining the distribution logic, Chunshuo reduced training variance and enhanced throughput across nodes. His work demonstrated depth in distributed systems engineering, prioritizing reliability and performance improvements over new feature development during this period, and contributed to more robust training pipelines.