Tools: Stop Rewriting Your Api: How Fmiddleware Lets You Deploy To Lambda...

You started with AWS Lambda even used a framework like Serverless.com. It made sense—no servers to manage, pay-per-use pricing, and quick deployments. Life was good.

The reality is that local development with Lambda is painful. You're constantly dealing with mocked API Gateway events, environment differences between local and deployed code, and debugging workflows that don't match how you'd normally work with Node.js. When something breaks in production, reproducing it locally means wrestling with event structures and Lambda-specific context objects.

And if your team ever decides to move to Docker or Kubernetes? Your entire codebase is tied to Lambda's event structure—migration means rewriting your API layer.

What if you could write your API handlers once and deploy them to any runtime without changing a single line of business logic?

FMiddleware is a framework-agnostic HTTP middleware library that abstracts away the runtime differences between AWS Lambda and Express.js. Your handlers stay the same—only the deployment wrapper changes.

Notice something? The handler code is identical. Only the wrapper changes.

No more mocking Lambda events or fighting with local emulators. Just run your Express server locally and test like any normal Node.js app:

When you're ready for production, deploy with your Lambda wrapper—zero code changes.

Already on Lambda and want to move to Docker? Simply:

Your handlers, validation, authentication—everything stays the same.

Source: Dev.to