During March 2026, Yeliex contributed to the fastify/fastify repository by developing comprehensive documentation for RFC 9457 Problem Details support in the @yeliex/fastify-problem-details plugin. This work focused on aligning Fastify’s error handling with structured, typed HTTP errors, providing clear guidance for developers integrating RFC-compliant error responses. Yeliex applied skills in API design, documentation, and error handling, using Markdown to ensure clarity and accessibility. The update addressed the need for standardized error reporting within the Fastify ecosystem, enhancing maintainability and developer experience. While the contribution was limited to documentation, it demonstrated a thoughtful approach to technical communication and ecosystem alignment.