Worked on the DefangLabs/defang repository to enhance reliability and maintainability of backend systems and CLI tools. Focused on Go-based development, the work included adding comprehensive unit tests and refactoring components such as Subscribe, WaitServiceState, and authentication flows to ensure robust error handling, retry logic, and correct behavior in both interactive and non-interactive scenarios. Addressed a CloudWatch Logs issue by refining filter pattern handling for empty strings, improving AWS integration and observability. Emphasized API integration, mocking, and testing to reduce defects and enable safer deployments, resulting in a more resilient authentication and service orchestration workflow across the platform.