2.1.1. AWS Lambda Fundamentals

First Principle: AWS Lambda allows developers to run code in response to events without provisioning or managing servers, enabling highly scalable, cost-effective, and agile application development.

AWS Lambda is a serverless compute service that executes your code only when needed and scales automatically. You pay only for the compute time consumed, eliminating idle costs.

Key Lambda Fundamentals:

• Execution Model: Code runs in response to events (e.g., S3 object creation, API Gateway request, DynamoDB stream changes).
• Serverless: No servers to provision, manage, or patch. AWS handles underlying infrastructure.
• Pay-per-use: Billed per invocation and compute duration (GB-seconds). No cost when idle.
• Automatic Scaling: Scales automatically to handle traffic spikes.
• Execution Environment: Lambda provides a secure and isolated environment for your code, including runtime support for popular languages (Node.js, Python, Java, C#, Go, Ruby, PowerShell).

Scenario: You need to build a backend service that runs a piece of code only when a specific event occurs, such as a new file being uploaded to an Amazon S3 bucket. You want to avoid provisioning and managing servers for this task.

Reflection Question: How does AWS Lambda's fundamental model of running code in response to events, without server management, enable you to build highly scalable and cost-effective applications, eliminating idle costs?