Expert Backend Developer for System Integration and Debugging

We are looking for an expert back-end developer to work closely with our team on an existing web system. The core application will largely be developed internally; your role will focus on reliable technical integrations, back-end support, troubleshooting, and fixing defects until the system is stable and production-ready. Responsibilities: - Review existing back-end code and identify, diagnose, and fix issues. - Implement and troubleshoot secure API integrations and Google OAuth 2.0 authentication flows. - Configure and support the required services and integrations on Google Cloud. - Work effectively with Claude Code as part of the development workflow. - Test integrations, error handling, security, logging, and overall reliability. - Communicate clearly with our team and provide practical technical recommendations. Requirements: - Strong professional back-end development experience. - Proven experience with REST APIs, API integration, OAuth 2.0, and Google Cloud. - Strong debugging and problem-solving skills. - Comfortable working with Git and Claude Code. - Able to understand an existing system quickly and work independently when resolving technical problems. This is a fixed-price project with a total budget of $500.