AWS Lambda Explained with a Simple Java Example
AWS Lambda is a fully serverless compute service that lets you run code without provisioning or managing servers. You are billed only for the time your function actually runs—unlike EC2, where you pay even when the server is idle. Lambda automatically scales, executes only when triggered, and shuts down after execution. What AWS Lambda Does Runs small pieces of code called functions written in Java, Python, Node.js, Ruby, and more. No server, OS, CPU, RAM, or patching management—AWS handles everything. Billed only per invocation and execution time. Ideal for event-driven, bursty, or low-traffic workloads. How AWS Lambda is Triggered A Lambda function does nothing until a trigger fires. Common triggers include: S3 — Run code when files are uploaded or deleted (e.g., image resizing). SQS / SNS — Process messages as they arrive. API Gateway — Build serverless REST APIs where each HTTP call invokes Lambda. EventBridge / CloudWatch — Cron jobs...