Worked on the prestodb/presto repository to improve build stability and module hygiene during an internal authentication migration. Addressed a classpath conflict by removing a duplicate BasicPrincipal class from the presto-main-base module, ensuring that authentication components were properly consolidated within presto-internal-communication. This change streamlined transitive dependencies and eliminated redundant code without impacting production environments. The solution was implemented in Java, leveraging skills in build management and dependency management to validate multi-module builds and confirm correct module relationships. Continuous integration and downstream checks were used to verify the fix, and documentation was updated to align with release notes and contributor guidelines.