Worked on the fastify/fastify repository to enhance security and reliability by addressing a vulnerability in the Proxy Trust Function. Focused on backend development and API security using JavaScript, the contribution involved gating host and protocol getters so they only process headers from trusted connections. This targeted bug fix mitigated header spoofing risks and aligned with current security advisories, resulting in a concise and auditable change with minimal impact on the codebase’s surface area. The approach demonstrated a strong understanding of security best practices and careful collaboration, improving the security posture for proxy deployments without introducing unnecessary complexity or overhead.