Worked on the jakartaee/platform-tck repository to stabilize the test baseline by reverting experimental Jakarta Transactions TCK tests. Focused on restoring the system to its pre-change state, this effort targeted tests related to read-only transactions and ExtendedXAResource functionality, addressing issues with test flakiness and maintenance overhead. Using Java and leveraging expertise in JTA and XA Transactions, the work ensured that the platform-tck remained compatible with Jakarta EE specifications and met continuous integration requirements. By validating build stability and updating baseline references in CI, the developer preserved release readiness and maintained a clean, reliable codebase for downstream consumers.