Worked on the keycloak/keycloak repository to enhance the correctness and reliability of LDAP group memberships by implementing recursive nested-membership resolution in the LDAP Group Mapper. Addressed issues with transitive group membership by ensuring users in sub-groups are accurately listed as members of parent groups, aligning member listings with effective role mappings. Utilized Java for backend development, focusing on LDAP handling, recursive traversal, and de-duplication strategies to improve scalability for large group hierarchies. Added comprehensive unit tests to validate recursive membership resolution, prevent regressions, and maintain test coverage, resulting in more accurate authorization and maintainable, well-documented code changes.