Lambda function in AWS

AWS Lambda is a serverless compute service that lets you run your code without provisioning or managing servers. You just write your function code, upload it, and Lambda takes care of executing it in response to events, scaling automatically, and managing infrastructure.

Key Points About AWS Lambda:

• Serverless: No servers to manage or provision. You just focus on your code.

• Event-driven: Lambda functions run in response to triggers such as:

  • API Gateway requests

  • Changes in S3 buckets (like file uploads)

  • DynamoDB streams

  • CloudWatch events and alarms

  • SNS notifications, and many more

• Auto-scaling: Lambda scales automatically based on incoming requests.

• Supports multiple languages: Node.js, Python, Java, C#, Go, Ruby, and custom runtimes.

• Execution time: Functions can run for up to 15 minutes per invocation.

• Stateless: Each invocation is independent; any state must be stored outside (e.g., DynamoDB, S3).

How it works:

1. Write your function code (for example, in Python or Node.js).

2. Set up triggers/events that invoke the function.

3. Lambda runs your code in a managed environment when triggered.

4. You pay only for the compute time your code actually consumes (billed per millisecond).