During November 2024, Chris Haynes focused on backend development for the cBioPortal/cbioportal repository, addressing a critical API security issue. He improved authentication and authorization handling by reordering Spring Security filter chains so that the API security chain executes before the OAuth2 chain. This adjustment ensures that API requests are authenticated and authorized in the correct sequence, reducing the risk of misrouted authentication flows. The solution was delivered as a single, auditable commit in Java, demonstrating a precise and targeted approach to security hardening. Haynes’s work reflects a deep understanding of Spring Security and backend architecture, though limited in scope.