API gateway concept in Express - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is an API Gateway in system design?

An API Gateway is a server that acts as a single entry point for all client requests to multiple backend services. It handles routing, authentication, rate limiting, and sometimes response aggregation.

beginner

Name two main responsibilities of an API Gateway.

1. Routing client requests to the correct backend service.<br>2. Handling security like authentication and authorization.

intermediate

Why use an API Gateway instead of direct client-to-service communication?

It simplifies client interactions by providing one endpoint, improves security by centralizing access control, and can improve performance by caching and aggregating responses.

intermediate

How does an API Gateway help with scalability?

It can balance load across multiple backend services and apply rate limiting to protect services from overload, helping the system scale smoothly.

advanced

What is a common challenge when using an API Gateway?

It can become a single point of failure or a bottleneck if not designed or scaled properly.

What role does an API Gateway play in a microservices architecture?

A Acts as a single entry point for client requests

B Stores all user data

C Replaces backend services

D Manages database transactions

An API Gateway acts as a single entry point that routes client requests to the appropriate backend services.

Which of the following is NOT a typical function of an API Gateway?

A Direct database management

B Authentication and authorization

C Request routing

D Rate limiting

API Gateways do not manage databases directly; they route requests and handle security and traffic control.

How does an API Gateway improve security?

A By encrypting backend databases

B By replacing firewalls

C By storing user passwords

D By centralizing authentication and authorization

API Gateways centralize security by managing authentication and authorization for all incoming requests.

What is a potential risk of using an API Gateway?

A It increases client complexity

B It can slow down the database

C It can become a single point of failure

D It eliminates the need for backend services

If not properly designed or scaled, the API Gateway can become a single point of failure.

Which feature helps an API Gateway protect backend services from too many requests?

A Caching

B Rate limiting

C Load balancing

D Data encryption

Rate limiting controls how many requests a client can make, protecting backend services from overload.

Explain the role and benefits of an API Gateway in a microservices system.

Think about how clients communicate with many services and how the gateway helps.

Describe common challenges when implementing an API Gateway and how to address them.

Consider what happens if the gateway goes down or gets overloaded.