During March 2026, Lin Zhao focused on security hardening within the fastify/fastify repository, addressing a critical vulnerability in the Proxy Trust Function. Lin implemented a targeted bug fix in JavaScript that gated host and protocol getters to process headers only from trusted connections, effectively mitigating header spoofing risks. This change, co-authored with Matteo Collina, aligned with current security advisories and improved the reliability of proxy deployments. Drawing on backend development and API development skills, Lin delivered a concise, auditable update that minimized surface area impact while enhancing security posture, demonstrating depth in applying security best practices to real-world codebases.