API Gateway Introduction and Types

Amazon API Gateway is the developer’s entry point into AWS-powered APIs. Whether we’re building RESTful microservices, low-latency backends, or real-time chat apps, API Gateway simplifies connectivity, security, and traffic management, all without managing infrastructure.

In the AWS Certified Developer – Associate (DVA-C02) exam, we’re expected to design and implement application workflows that use Amazon API Gateway to expose and manage backend functionality. We’ll learn how to set up different types of APIs (REST, HTTP, or WebSocket) and how to decide which type best fulfills our needs. These are core developer skills tested on the exam and critical for building real-world serverless and event-driven applications on AWS.

What is Amazon API Gateway?

Amazon API Gateway allows us to expose REST, HTTP, or WebSocket endpoints and route them to AWS services like Lambda, DynamoDB, and more. It abstracts the complexity of infrastructure provisioning, authorization, transformation, throttling, caching, and monitoring.

Rather than managing API servers ourselves, we rely on API Gateway to handle request validation, traffic management, and endpoint scaling. It also integrates natively with IAM, Cognito, CloudWatch, and X-Ray, allowing us to build secure and observable APIs.

Why developers use API Gateway

API Gateway is central to building decoupled, event-driven, and serverless applications on AWS. We can easily connect frontend clients to Lambda functions, configure different behaviors per environment using stage variables, and enforce authorization rules with minimal custom code.

From a developer’s standpoint, API Gateway helps us:

• Rapidly prototype and launch APIs.

• Apply throttling and usage controls.

• Define validation rules and ...