Worked on the elastic/elasticsearch repository to enhance the stability of the PromQL Logical Plan Optimizer, focusing on backend reliability and build consistency. Addressed a critical compilation error by updating the EsIndex constructor with a new parameter, which ensured that the PromQL feature functioned correctly and prevented test failures during continuous integration. This targeted fix maintained API compatibility while improving the robustness of the build process. Leveraged Java for backend development and rigorous testing, demonstrating attention to detail in identifying and resolving issues that could impact CI reliability. The work contributed to a more stable development workflow without introducing new features.