I need a Node.js developer who can quickly wire up our backend to a third-party service. The job is straightforward: create the REST calls, handle OAuth authentication, and move product data back and forth in clean JSON. Because we may plug this work into either an existing codebase or a fresh project—the decision is still open—I’m looking for tidy, well-commented code that can drop into either scenario without fuss. You should be comfortable testing endpoints in Postman (or any similar tool) and delivering sample requests, responses, and error cases so I can verify everything on my side. Deliverables: • A small, self-contained Node.js module that authenticates via OAuth and exposes functions for the required endpoints • Clear setup notes (env variables, routes, any middleware) • Postman collection or curl samples demonstrating successful requests and responses for each call If you’ve integrated external APIs before—especially where OAuth and product catalogs are involved—please highlight that so I can gauge fit quickly. I expect this to be a few hours of focused work for someone experienced, and I’m ready to review your proposal right away.