Worked on the uber/cosmo repository to enhance the security and reliability of its WebSocket subsystem. Addressed a critical issue by fixing the leakage of negotiation headers to subgraph WebSocket connections, thereby reducing the risk of sensitive information exposure during real-time communication. The solution involved strengthening header isolation and ensuring proper management throughout the negotiation process, all while maintaining minimal performance impact. Utilized Go for backend development and testing, with careful attention to traceability by referencing related issues in commit messages. This targeted bug fix improved the overall stability of WebSocket flows and supported future audits and code reviews.