Worked on the HDRUK/gateway-api repository to address a critical issue in NHSE SDE access expiry handling. Focused on backend development using Laravel and PHP, the work involved correcting an incorrect configuration key reference in the cohort expiry command, ensuring that access expiry now accurately reflects the intended five-year duration. To reinforce reliability and policy compliance, unit and feature tests were expanded to validate the updated expiry logic and prevent future regressions. This targeted bug fix improved expiry-related workflows and enhanced test coverage, supporting more dependable calculations and maintaining alignment with business requirements for access control and data governance.