I need a developer who can design and implement an API connection from scratch, then integrate it smoothly into my existing system. I am flexible on the architecture—RESTful, GraphQL, or even SOAP—so please suggest the approach you feel best suits modern maintainability and performance. Because the system’s purpose is still being refined, the API should be built in a way that can serve multiple potential use-cases, such as: • syncing data with external partners, • feeding internal applications, • or acting as a gateway for future third-party services. Key expectations • End-to-end setup: specification, development, basic documentation, and a tested deployment. • Secure authentication and solid error handling. • Clear code comments plus a concise README so my in-house team can extend the work later. • A short hand-over call or screen-share to walk through endpoints and configurations. If you have experience with scalable back-end frameworks (Node.js, Django, .NET, or similar) and can point to previous API projects, I’d love to see them.