Top 15 RESTful Web Services Interview Questions and Answers

By Indeed Editorial Team

Updated September 8, 2021 | Published February 25, 2020

Updated September 8, 2021

Published February 25, 2020

The Indeed Editorial Team comprises a diverse and talented team of writers, researchers and subject matter experts equipped with Indeed's data and insights to deliver useful tips to help guide your career journey.

Many jobs in programming and web development require an understanding of RESTful web services. Since this is a specialized technical skill, interviewers will likely ask questions about your practical experience as well as several questions to test your knowledge.

Reviewing the basic concepts of RESTful web services before an interview can prepare you to give the most accurate answers and impress the interviewer. In this article, we share 15 common interview questions that assess restful web services skills and their answers.

Related: Learn About Being a Computer Programmer

Interview questions with sample answers

With RESTful services requiring specialized knowledge, you should expect that your interview questions will demand you to demonstrate some degree of knowledge. Here are some examples:

  • What are web services?

  • What does REST stand for?

  • What are RESTful web services?

  • Which protocol does RESTful web services use?

  • What is statelessness and what are its advantages and disadvantages?

  • What is caching?

  • What are the best practices for caching?

  • What are the most common HTTP methods used in RESTful web services?

  • What is a resource in REST and how are they represented?

  • What is messaging in RESTful web services?

  • What are the main parts of an HTTP request?

  • What is a URI and what is its purpose?

  • What are the best practices for creating a URI?

  • What are idempotent operations?

  • What is the function of an HTTP status code?

What are web services?

Interviewers will ask this question to see if you are comfortable explaining basic concepts about programming and web development. It can also be used to set up more complicated questions later on in the interview.

Example: "Web services are the ways that data can be exchanged between different types of software and applications. They use computer networks to communicate information based on a specific set of rules and protocols."

What does REST stand for?

This question helps the interviewer test your ability to recall information and your general knowledge about RESTful web services. Providing a correct definition of REST will introduce your qualifications and show that you are a serious candidate.

Example: "REST stands for Representational State Transfer."

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What are RESTful web services?

Your answer to this question should be accurate and show your confidence in your knowledge. Include examples of what RESTful services do.

Example: "RESTful web services are a standardized set of programming rules that allow clients to access and modify data resources within a network, such as the internet. They use simple techniques to allow a server to connect to resources such as pictures, videos or web pages.

Which protocol does RESTful web services use?

This question can help employers identify candidates that are not familiar with the terms used in programming. While protocol can mean any set of rules, in RESTful web services jobs, it refers to a specific web program. Sometimes, short and to the point will suffice.

Example: "RESTful web services use HTTP protocols."

What is statelessness and what are its advantages and disadvantages?

Since statelessness is a key concept in RESTful web services jobs, you should be able to confidently explain its benefits and limitations.

Example: "Statelessness occurs when a server does not store a client's information, so each interaction with their server cannot be influenced by outside factors. One disadvantage of statelessness is that clients will have to provide their information every time they use their server. However, statelessness can allow clients to make their applications simpler and easier to maintain."

What is caching?

Many people who use the internet have a basic understanding of caching, but it has a specific purpose when working with RESTful web services. When answering this question, be sure to explain why caching is important in RESTful web services, specifically.

Example: "Caching in RESTful web services is when clients store a specific type of information for a limited period of time. Since many RESTful web services are stateless, caching allows clients to save some types of information when they know they will be interacting with a server several times about the same resource."

What are the best practices for caching?

Employers look for candidates that are aware of the accepted methods or best practices within their field. Your answer to this question will show that you have high standards for the quality of your work.

Example: "Information that is static and doesn't change—such as images or CSS—should expire after two or three days. Resources that are regularly updated should not be cached for more than a few hours. This helps keep the web services simple and stateless."

What are the most common HTTP methods used in RESTful web services?

This question will give you a chance to show that you can apply your knowledge of REST to situations in the workplace. You should be able to explain each method because working with REST requires you to use them regularly.

Example: "There are five common HTTP methods in RESTful web services: get, put, delete, post and options. 'Get' lets clients read a resource, 'put' lets clients create a new resource, delete' lets clients remove a resource, 'post' can create a new resource or update a current resource and 'options' lists what each resource can do."

What is a resource in REST and how are they represented?

Interviewers often look for candidates who understand the meaning of their work in addition to how to complete it properly. When answering this question, explain the significance of resources instead of simply providing a definition.

Example "A resource is any form of data in a computer network. They can be images, text files, web pages and other content. RESTful web services are used to let clients easily access these resources. They are usually represented by JSON and XML formats.

What is messaging in RESTful web services?

Employers ask questions about REST messaging to see that you have the ability to troubleshoot. This question allows you to show your ability to communicate using standard methods in RESTful web services.

Example: "In RESTful web services, clients interact with servers by sending and receiving messages. Messaging includes an HTTP request that the client sends to the server and an HTTP response that shares information about a resource."

What are the main parts of an HTTP request?

Employers ask this question to test a candidate's ability to identify and sort information. You should know each part of the operations you perform, their importance and how to recognize them.

Example: "The main parts of an HTTP request are the verb or HTTP methods, the URI, the HTTP version, the header and the body of the message."

What is a URI and what is its purpose?

There are many abbreviations regularly used in programming and web development. Interviewers may ask you to define URI to ensure that you have a strong understanding of the phrases you use.

Example: "URI stands for Uniform Resource Identifier and is used to uniquely name each resource in a RESTful web service. Clients use URIs to find the location of each resource on the server."

What are the best practices for creating a URI?

Employers will often ask this question to ensure that you know the rules to keep their web service running smoothly.

Example: "When creating a standard URI, you have to keep the format simple and consistent. Use lowercase letters, plural nouns and HTTP verbs such as 'delete' to simplify the name and make it unique. You should use underscores or hyphens instead of spaces."

What are idempotent operations?

This question can determine how much you know about the specifics of REST. There are only two idempotent operations, so the employer will be looking for a particular answer that only qualified candidates will know.

Example: "Idempotent operations are actions that will always be the same within a network. 'Put' and 'delete' are the two idempotent operations."

What is the function of an HTTP status code?

Employers may ask this question to check if a candidate understands the purpose of their work in RESTful web services. They may also ask about the meanings of specific status codes.

Example: "HTTP status codes are a set of codes that relay information to someone accessing a resource using its URI. They tell users about the state of the data they want to look up. For example, HTTP 400 means that the request was incorrectly formatted, while HTTP 404 means the resource is not on the server."

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