In March 2026, Zhen worked on the bytedance/deer-flow repository, delivering core improvements to the LangGraph server’s performance and reliability. He enhanced backend concurrency to allow multiple conversation runs in parallel and introduced environment-based tracing configuration, streamlining observability without explicit docker-compose overrides. Using Python, Docker, and YAML, Zhen automated virtual environment dependency synchronization before service startup, reducing runtime errors from outdated packages. He also fixed a bug to ensure tracing values from environment files are respected, supporting consistent monitoring across deployments. These changes improved development workflow, reduced latency under load, and enabled faster iteration cycles for both feature development and debugging.