Worked on the keycloak/keycloak repository to enhance URI validation security by addressing encoded path traversal vulnerabilities. Focused on tightening the UNSAFE_PATH_PATTERN using advanced regex techniques in Java, the update blocked additional encoded terminators such as semicolons and control characters. The approach maintained alignment with RFC 3986 and preserved existing service behavior, minimizing regression risk. Comprehensive unit testing was performed, including expanded assertions and negative tests to ensure legitimate URIs remained resolvable. Integration tests and expectations were updated across modules, with all changes locally verified. This work demonstrated depth in back end development, regex, and robust test-driven engineering practices.