API Gateway

aws/networking aws/service

💡 Definition

Amazon API Gateway is a fully managed service that makes it easy for developers to create, publish, maintain, monitor, and secure APIs at any scale.

🔑 Key Concepts

API Management: Handles all the tasks involved in accepting and processing up to hundreds of thousands of concurrent API calls.
Backend Integration: Can integrate with Lambda functions, EC2 instances, or any web application.
Security: Provides features like IAM authorization, Cognito User Pools, and API keys.
Traffic Management: Handles request throttling, caching, and routing.
Monitoring: Integrates with CloudWatch to monitor API calls and data.

⚙️ How it Works

API Gateway acts as a "front door" for applications to access data, business logic, or functionality from your backend services. It takes client requests, routes them to the appropriate backend, and returns the response.

🎯 Use Cases

Building RESTful APIs: For web and mobile applications.
Serverless Backends: Connecting web/mobile apps to Lambda functions.
Microservices: Exposing microservices via a single, managed API.

💰 Pricing Model

API Calls: Charged per million API calls received.
Data Transfer Out: Charged for data transferred out of API Gateway.
Caching: Optional caching incurs additional cost.

📝 Exam Tips (CLF-C02)

It's a fully managed service for building and managing APIs.
Often used to trigger Lambda functions.
Handles traffic management, authorization, and monitoring.
Can expose HTTP/S endpoints for your services.

See Also: * Lambda * EC2 * Load Balancer