Worked on the goauthentik/authentik repository to enhance security and interoperability in the OAuth and OIDC authentication flow. Addressed a critical compliance issue by updating the PKCE code verifier length to 128 characters, aligning with RFC 7636 requirements and improving compatibility with PKCE-compliant identity providers. Utilized Python to implement the fix and added automated tests to ensure future changes maintain the correct verifier length, reducing the risk of integration failures. Focused on API development and testing, the work was delivered with clear documentation, clean commit history, and adherence to standard contributor practices, supporting maintainability and auditability of the codebase.