Over two months, contributed backend features to grafana/mcp-grafana and StarRocks/starrocks, focusing on robust error handling and database integration. Developed a centralized error handling system in Go for Prometheus and Loki validation, introducing typed errors to distinguish user input issues from system failures, which improved client-side error recovery and observability. Enhanced Loki metric querying by refining label parsing and supporting both instant and range queries. In Java, added a schema_resolver property to the JDBC catalog in StarRocks, increasing compatibility with non-standard JDBC drivers and diverse databases. Emphasized maintainability, clear error propagation, and flexible API design throughout the work.