Worked on improving error handling within the apache/pinot repository by addressing inconsistencies in query validation error reporting. Focused on backend development using Java, the work involved refactoring the system to map BadQueryRequestException to QueryException.QUERY_VALIDATION_ERROR, ensuring that query validation errors are reported uniformly throughout the platform. This change enhanced the clarity and reliability of error messages and associated metrics, supporting better exception management and query processing. The contribution centered on fixing a specific bug rather than adding new features, demonstrating attention to detail in maintaining robust error handling practices within a complex distributed data infrastructure.