Serverless Express is a Node.js adapter that enables Express and other web frameworks to run on AWS Lambda, API Gateway, Lambda@Edge, and Azure Functions.
The tool solves the problem of deploying traditional Node.js web applications to serverless platforms without rewriting application code. It works by wrapping your Express application in a minimal Lambda handler that translates API Gateway events into standard HTTP requests and converts responses back into the format Lambda expects. This allows developers to keep their existing Express routing, middleware, and business logic intact while gaining the benefits of serverless deployment.
Teams should adopt this tool if they have existing Express applications they want to migrate to AWS Lambda or are building new REST APIs that benefit from serverless scaling and pay-per-use pricing. It suits projects of any size that need to run on Lambda with API Gateway, ALB, or Lambda@Edge. The tool supports async setup in Lambda handlers, enabling initialization logic that runs once per container. Developers migrating from traditional servers will find the approach familiar since application code remains largely unchanged.
The project maintains active support for current Node.js versions and has released major updates that remove deprecated APIs while adding compatibility with newer runtimes. Development activity shows ongoing maintenance with attention to breaking changes, as evidenced by clear upgrade documentation provided between major versions. The project includes example starter applications and helper scripts to reduce friction for new users getting applications deployed.
