Lambda allows you to run code without provisioning servers. Python, Node.js, C#, and Java programming languages are all currently supported. Scale is handled automatically. You only pay when your code executes. Everything runs in parallel and your code needs to either be stateless or manage state in an external database. The code is essentially event-driven since you configure when and under what conditions it executes.

Using a service such as Lambda is often referred to as serverless computing and opens up a whole new range of possibilities. You could create a fully-functional web application with Lambda that has no server behind it. You can create analytic code that scales to millions of device events without ever having to worry about managing a server. The following diagram gives an overview of how it works in practice: