Worked on stabilizing metadata-driven queries in the langgenius/dify repository by addressing a critical issue related to metadata filter validation. Using Python and backend development skills, implemented early checks to detect when the metadata filter constant was None or blank, introducing guard clauses and aborting processing in such cases. This approach prevented SQL errors and reduced the risk of runtime exceptions in data handling workflows. The targeted fix improved the reliability and data integrity of metadata-dependent query paths, contributing to the overall operational stability of the repository. The work demonstrated careful attention to error prevention and robust backend engineering practices.