AWS Lambda and Serverless Function Patterns#

Lambda runs your code without you provisioning or managing servers. You upload a function, configure a trigger, and AWS handles scaling, patching, and availability. The execution model is simple: an event arrives, Lambda invokes your handler, your handler returns a response. Everything in between – concurrency, retries, scaling from zero to thousands of instances – is managed for you.

That simplicity hides real complexity. Cold starts, timeout limits, memory-to-CPU coupling, VPC attachment latency, and event source mapping behavior all require deliberate design. This article covers the patterns that matter in practice.