Worked on stabilizing authentication flows in the instantdb/instant repository by addressing a critical issue with Apple Sign-In after changes in OpenID issuer metadata. Implemented a robust issuer validation fix in Clojure, ensuring compatibility with both known Apple issuer URLs and maintaining uninterrupted authentication for users. Focused on backend development and authentication, the solution reduced production risk and minimized user impact by preventing sign-in failures. The work emphasized code quality and traceability, with clear commit messaging linked to the relevant issue for future audits. This targeted bug fix preserved authentication reliability without introducing new features during the development period.