2.2.2. AWS Lambda

💡 First Principle: AWS Lambda runs code in response to events without requiring users to provision or manage servers, enabling highly scalable, cost-effective, and agile application development through event-driven architectures.

AWS Lambda is a serverless compute service. It allows you to run code without provisioning or managing servers. You upload your code, and Lambda handles all the infrastructure management, including server provisioning, scaling, patching, and maintenance.

Key Characteristics of AWS Lambda:

• Serverless: You don't manage any servers.
• Event-Driven: Code (a "Lambda function") is invoked (runs) only in response to specific events (e.g., a file upload to Amazon S3, an HTTP request via API Gateway, a database change in Amazon DynamoDB).
• Automatic Scaling: Automatically scales to handle any volume of incoming events, from a few requests per day to thousands per second.
• Pay-per-use: You pay only for the compute time consumed when your code is running (billed by the millisecond). There are no charges when your code is idle.
• Supported Runtimes: Supports popular programming languages like Node.js, Python, Java, C#, Go, Ruby, and PowerShell.
• Use Cases: Building backend APIs, data processing, real-time file processing, automating IT tasks, chatbots.

Scenario: A company needs to automatically resize images whenever a new image is uploaded to their website's storage. They want a solution that scales automatically with image uploads and has no cost when no images are being uploaded.

Reflection Question: How does AWS Lambda's "serverless" and "event-driven" model fundamentally allow a business to run code in response to events without managing servers, enabling automatic scaling and cost-effectiveness by only paying for what they use?