Diyar Joshy contributed to the EbookFoundation/free-programming-books repository by adding a new course entry for CS50's Introduction to Cybersecurity, broadening the repository’s coverage of cybersecurity topics for learners. He managed content curation and educational resource integration using Markdown, ensuring the new resource was discoverable and aligned with open-source learning objectives. Diyar followed precise git-based workflows, collaborating with external course authors and maintaining repository standards through clear commit messages and proper attribution. While the work focused on a single feature addition, it demonstrated careful attention to content management and educational value, enhancing the repository’s breadth without introducing new bugs or regressions.