Worked on the EbookFoundation/free-programming-books repository to enhance the reliability of programming cheatsheets by addressing broken external links. Applied documentation and Markdown skills to identify dead or outdated URLs, then redirected users to archived versions via the Wayback Machine, ensuring continued access to valuable educational resources. Added clear archival indicators to maintain transparency for learners navigating the material. Coordinated a single commit that resolved multiple 404 errors, reducing user friction and potential support requests. This work preserved the long-term value of the repository as a stable reference hub for programming, with a focus on sustainable resource accessibility and user trust.