Over a two-month period, contributed backend enhancements to the prestodb/presto repository, focusing on error handling and system observability. Developed a new error path to explicitly identify queries terminated due to cluster overload, introducing a dedicated error code and refactoring user-facing reporting for greater clarity. Leveraged Java and SQL to improve operational visibility and streamline troubleshooting for query termination events. Additionally, enhanced testing for materialized view rewrites by creating a helper to assert runtime metrics, migrating planner tests for improved reliability. Emphasized robust test coverage and maintainability, ensuring all changes reduced regression risk and supported future monitoring and automation efforts.