During September 2025, Hesongyi Song worked on the coinbase/x402 repository, focusing on modernizing backend infrastructure by updating dependencies to support the latest Jakarta Servlet API and Jetty server. Using Java and Maven, Hesongyi removed deprecated libraries and legacy dependencies, ensuring the codebase aligned with Jakarta EE standards. This targeted feature work provided a clear upgrade path, reduced runtime risks during deployments, and simplified future maintenance. The changes preserved existing functional behavior and security, while enabling smoother deployments. Hesongyi’s contribution demonstrated depth in backend development, emphasizing compatibility and maintainability through a focused, high-impact commit that future-proofed the repository.