Stop Writing Boilerplate File Upload Code in NestJS — Here's a Better Way

If you've ever built file upload functionality in NestJS, you know the pain. This post is for you. The All-Too-Familiar Story You're building a NestJS backend. The product team wants file uploads — avatars, documents, whatever. Simple enough, right? Then reality sets in. You wire up multer, wrestle with S3's SDK, write a wrapper service, add a custom interceptor, figure out how to validate file types (and realize checking the extension isn't safe), figure out what happens when you need to test all this, and then the stakeholder says: "Can we support Google Cloud Storage too? We're moving vendors next quarter." And you're back to square one. The Real Pains Every NestJS Developer Faces Before we get to the solution, let me name the actual problems — because they're specific, and they're solvable. Pain 1: Every Cloud Provider Has a Different API With S3, you use @aws-sdk/client-s3 . With GCS, you use @google-cloud/storage . With local dev, you use fs . None of these are interchangeable. Y