📖 What is API Gateway?

API Gateway is a fully managed service that facilitates the creation, publication, maintenance, monitoring, and security of APIs at scale. It acts as a reverse proxy, handling tasks like authentication, authorization, rate limiting, and request transformation, enabling secure access to backend services.

🥋 Sensei Says:

"Focus on API Gateway’s role in microservices architectures. Understand how it decouples front-end applications from backend services. Be prepared to identify use cases where API Gateway provides value, such as managing traffic, enforcing security policies, and simplifying application integration."

📚 Certification: AWS Certified Cloud Practitioner (CLF-C02)

🔑 What are the Key Concepts of API Gateway?

  • API Gateway decouples front-end applications from backend services, enabling independent scaling and development of each layer.
  • It handles cross-cutting concerns like authentication, authorization, and rate limiting, reducing complexity in backend code.
  • API Gateway supports various API types (REST, HTTP, WebSocket) and integrates with other AWS services like Lambda and EC2.
  • Caching capabilities within API Gateway improve performance and reduce load on backend systems by storing frequently accessed data.
  • Usage plans and API keys allow for controlled access and monetization of APIs, essential for public-facing services.

🎯 How does API Gateway appear on the CLF-C02 Exam?

You may be asked to identify the AWS service best suited for managing and securing access to a serverless application built with Lambda functions.

A scenario might describe a mobile application needing to access data from multiple microservices – determine how API Gateway simplifies this integration.

Expect questions about how to use API Gateway to implement rate limiting to protect backend resources from being overwhelmed by excessive requests.

❓ Frequently Asked Questions

Can API Gateway be used with on-premises backend services?

Yes, through Private APIs, API Gateway can securely access backend services hosted within your VPC, extending its benefits to hybrid architectures.


What is the difference between an Edge-optimized and Regional API Gateway?

Edge-optimized is best for global access with low latency, leveraging CloudFront. Regional is ideal for VPC-internal APIs or when data residency is critical.


How does API Gateway integrate with AWS WAF?

API Gateway integrates seamlessly with AWS WAF, allowing you to protect your APIs from common web exploits like SQL injection and cross-site scripting.

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