20 API Gateway Interview Questions and Answers

An API gateway is a server that acts as an intermediary between a client and a group of microservices. When applying for a position that involves working with an API gateway, you can expect to be asked questions about your experience and knowledge of the subject. In this article, we will review some of the most common questions asked about API gateways and how you should answer them.

API Gateway Interview Questions and Answers

Here are 20 commonly asked API Gateway interview questions and answers to prepare you for your interview:

1. What is an API gateway?

An API gateway is a type of proxy server that sits between client applications and backend services in order to facilitate communication between the two. An API gateway handles requests from clients, forwards them to the appropriate backend service, and then returns the response back to the client. API gateways can also provide additional features such as authentication, rate limiting, and caching.

2. How does the API gateway work in a microservices architecture?

The API gateway is the entry point for all client requests. It is responsible for routing requests to the appropriate microservice, and for providing any necessary authentication and authorization. The API gateway also handles any cross-cutting concerns, such as monitoring and logging.

3. Can you explain how to create a simple REST API using AWS API Gateway?

To create a simple REST API using AWS API Gateway, you will need to create a new API, create a resource for the API, create a method for the resource, and deploy the API. The API Gateway will then provide you with an endpoint that you can use to access the API.

4. What are some advantages of using API gateways with microservices architectures?

API gateways can provide a number of advantages when used with microservices architectures. They can help to provide a single point of entry for all microservices, which can make it easier to manage and monitor traffic. They can also help to provide security and authentication for all microservices, and can help to route traffic to the appropriate microservices.

5. What are the main components of Amazon API Gateway?

The main components of Amazon API Gateway are:

– The API Gateway service itself
– The API Gateway console
– The API Gateway API
– The API Gateway SDK

6. How do you configure authentication and authorization for your APIs?

When configuring authentication and authorization for APIs, you will need to use a combination of both. Authentication will ensure that only authorized users can access the API, while authorization will determine what level of access each user has.

7. How would you use Amazon’s CloudWatch service to monitor log data?

Amazon CloudWatch is a web service that provides real-time monitoring of Amazon Web Services (AWS) resources and applications. You can use Amazon CloudWatch to collect and track metrics, collect and monitor log files, set alarms, and automatically react to changes in your AWS resources.

8. Which AWS services can be used with API Gateway?

API Gateway can be used with a number of AWS services, including Lambda, DynamoDB, and S3.

9. What security protocols can be used with AWS API Gateway?

AWS API Gateway supports a number of different security protocols, including SSL/TLS, OAuth 2.0, and IAM.

10. How can you cache responses from an API endpoint?

One way to cache responses from an API endpoint is to use a content delivery network (CDN). A CDN can cache static content from your API endpoint and deliver it to users more quickly. Another way to cache responses is to use a reverse proxy server. A reverse proxy server can cache API responses and return them to users without having to send a request to the API endpoint each time.

11. What are some best practices when designing APIs?

Some best practices when designing APIs include using a consistent naming convention, using clear and concise documentation, and providing multiple ways to access the API (e.g. REST, SOAP, etc.).

12. What are some common problems that developers encounter when working with API Gateways?

Some common problems that developers encounter when working with API Gateways include:

– Difficulty understanding how the gateway works
– Lack of documentation or poor documentation
– Lack of support from the gateway provider
– Limited functionality of the gateway
– Poor performance of the gateway

13. What is the difference between private, public, and partner APIs?

Private APIs are internal to an organization and are not accessible to the public. Public APIs are open to anyone and are usually well-documented. Partner APIs are for use by approved partners and usually have some level of access control.

14. What is meant by throttling and what strategies might you employ when dealing with it?

Throttling is the process of limiting the amount of traffic that is allowed to flow through an API gateway. This can be done for a variety of reasons, such as to prevent overloading the backend systems that the API is connecting to, or to enforce rate limits for individual users. There are a number of different throttling strategies that can be employed, such as limiting the number of requests that can be made per second, or capping the total amount of data that can be transferred in a given period of time.

15. How does Amazon API Gateway handle CORS (cross-origin resource sharing)?

Amazon API Gateway handles CORS by allowing developers to specify which origins are allowed to access their API. This is done by setting up a CORS policy, which can be done either through the API Gateway console or through the API Gateway REST API. Once a CORS policy is in place, API Gateway will automatically add the necessary headers to responses from the API, allowing browsers to determine whether or not they should be allowed to access the resources.

16. What happens if an API request exceeds the concurrent throttle limit or rate limits set on an API?

If an API request exceeds the concurrent throttle limit or rate limits set on an API, then the API Gateway will return an error message to the client. The client will then need to either wait for the throttle limit to reset or try again later.

17. Is it possible to create a “custom domain name” for APIs created with Amazon API Gateway?

Yes, it is possible to create a custom domain name for APIs created with Amazon API Gateway. This can be done by creating a new Domain Name System (DNS) record that points the custom domain name to the Amazon API Gateway endpoint.

18. Do all requests made to an API get logged? If yes, then where?

All requests made to an API do get logged. The logs are typically stored in a database, and they can be used to track API usage and performance.

19. Why should I choose Amazon API Gateway over other solutions like Microsoft Azure API Management Service or Apigee?

There are many reasons you might choose Amazon API Gateway over other API management solutions, but some key reasons include the fact that Amazon API Gateway is fully managed by Amazon, so you don’t have to worry about maintaining or scaling the service yourself. Additionally, Amazon API Gateway integrates with other AWS services like Lambda and DynamoDB, making it easy to build serverless applications. Finally, Amazon API Gateway offers a free tier of service that allows you to get started without incurring any costs.

20. When should I use the “mock integration” option and when should I use the HTTP proxy integration option with Amazon API Gateway?

The “mock integration” option should be used when you want to return a pre-determined response from your API without having to set up any backend infrastructure. The HTTP proxy integration option should be used when you want to send requests through to a backend HTTP server.