Overview

Think of AWS Lambda as a way to run code without worrying about servers at all. Instead of maintaining a server that runs all the time, Lambda lets you upload your code and only runs it when needed. It's like having a computer that springs to life when there's work to do, and completely disappears when there isn't.

Lambda automatically handles all the infrastructure, scaling, and maintenance. You just provide the code (called a "Lambda function"), and specify when it should run. This could be in response to events (like a file being uploaded to S3), on a schedule, or when someone makes a request to your API.

Each Lambda function is small, focused, and independent. They're perfect for tasks that need to happen quickly and don't require a constantly running server. Lambda can scale automatically from a few requests per day to thousands per second.

The "serverless" aspect means you never have to patch, maintain, or administer servers. You also only pay for the exact amount of compute time you use, down to the millisecond, making it very cost-effective for sporadic workloads.

Example uses

Image Processing: When someone uploads an image to S3, a Lambda function automatically creates thumbnails or resizes the image for different devices.
Automated Backups: A Lambda function runs on a schedule to backup databases or create snapshots of resources.
Web APIs: Lambda can handle API requests, like checking a user's account balance or processing a form submission, without running a constant web server.
Data Processing: When new data arrives (like sales records or log files), Lambda can process, filter, and store that data automatically.

Integration with other AWS services

Lambda works particularly well with other AWS services, such as:

Amazon S3: Lambda can process files as soon as they're uploaded to S3 buckets. For example, processing images or analyzing documents.
Amazon API Gateway: Create APIs that trigger your Lambda functions when someone makes a request, perfect for building serverless web applications.
Amazon DynamoDB: Lambda can respond to changes in your DynamoDB tables or perform database operations without maintaining a database server.
Amazon CloudWatch: Can trigger Lambda functions on a schedule (like a cron job) or process CloudWatch log data automatically.
AWS SNS/SQS: Lambda can process messages and events from these messaging services, making it great for building event-driven applications.