Worked on the vllm-project/aibrix repository to enhance session-affinity routing by addressing a critical issue with the preservation of the x-session-id header. Focused on backend development and API reliability, the work involved updating header handling logic in Go to ensure that user session identifiers were consistently propagated across requests. Automated tests were added to validate the new behavior and prevent future regressions, emphasizing a test-driven approach. This improvement increased the reliability of session routing and contributed to a smoother user experience. The work demonstrated attention to detail in backend systems, with a focus on robust API development and comprehensive testing practices.