DevOps Dictionary

AWS Lambda is AWS’s serverless compute service for running code as event-driven functions without provisioning or managing servers. You package a function, choose a runtime (such as Node.js, Python, or Java), and connect it to triggers like API Gateway requests, S3 object uploads, DynamoDB stream updates, or SQS messages; Lambda then starts the execution environment, runs the handler, and scales the number of concurrent invocations automatically, billing mainly for requests and execution time. With AWS Lambda, teams can build APIs and background processing that scale on demand with minimal patching and capacity planning, while without it you typically run always-on VMs or containers, maintain scaling rules, and pay for idle compute during low traffic. This gap exists because Lambda manages scheduling, isolation, and integration with AWS event sources for each invocation.