Tahir Abbasi contributed to both the hmcts/probate-frontend and hmcts/probate-back-office repositories, focusing on accessibility, maintainability, and operational efficiency. In the frontend, he improved semantic HTML by updating the cookie banner heading and enhanced automated accessibility testing by filtering out known warnings, using JavaScript and HTML to support better user experience and test reliability. On the backend, Tahir permanently enabled alias transformation and duplicate executor filtering features, removing feature flags and cleaning up dead code in Java. His work reduced technical debt, simplified configuration, and improved release predictability, demonstrating depth in API development, backend engineering, and code refactoring.