DevOps Dictionary

AWS Lambda is a serverless compute service that runs your code in response to events, such as an HTTP request, a message arriving on a queue, or a file being uploaded to object storage. It addresses the problem of provisioning and operating servers for workloads that are bursty, event-driven, or hard to predict. At a high level, you package a function (a small unit of code) and configure triggers; Lambda automatically starts the needed runtime, executes the function, scales concurrency up and down, and charges only for the time spent running.

With AWS Lambda, teams can ship event-driven features quickly and rely on automatic scaling and built-in availability; without it, you typically run always-on services or scheduled workers, which increases operational overhead, idle cost, and the risk of capacity mis-sizing during traffic spikes. This gap exists because Lambda abstracts away the underlying fleet management and auto-scaling logic that you would otherwise build and maintain yourself.