Redux is an open-source library in JavaScript, which is popular in the domain of React and React Native. The fundamental principles of Redux help programmers achieve consistency throughout the applications they build, making testing and debugging easier. During an interview, recruiters may ask a variety of questions to determine how you use the library to manage and update the state of an application and why you are passionate about JavaScript development.

In this article, Pritish Kumar Halder list some general and in-depth Redux interview questions and share answers to five questions to help you prepare for your interview.

General Redux Interview Questions

Here are some general Redux interview questions that may allow interviewers to assess your personality and work ethic:

  1. What are the career goals that you have planned for yourself?

  2. What interests you to apply for the position of frontend developer in our company?

  3. The routine responsibilities of a programmer can be stressful. What steps do you take to better manage stress?

  4. What motivated you to become a frontend developer?

  5. Can you list some of your areas of improvement in the workplace?

  6. What are your strengths as a developer?

  7. What is your approach to cordially collaborating with team members and seniors?

  8. Can you tell us about times when an employer required you to work with minimal supervision?

  9. What, according to you, is success?

  10. Why do you think you are a suitable candidate for the frontend developer position in our company?

Questions About Background And Experience

Here are some questions that interviewers may ask professionals working with Redux to assess their educational qualifications and work experience:

  1. What is your work experience as a developer who uses JavaScript and Redux?

  2. Tell us about your collaborations with growth engineers and product managers.

  3. Tell us about a project that was challenging for you in this role.

  4. Why do you think your educational qualifications align with this role?

  5. Do you have experience with browser-based debugging, performance testing software tools and backend services?

  6. What is your level of experience working with ReactJS concepts and workflows?

  7. How well do you work with executive team members and other stakeholders?

  8. What tool do you use to efficiently accomplish your tasks?

  9. What experience do you have with performance testing frameworks?

  10. Do you have additional certifications or licences?

In-Depth Questions

Here are some in-depth questions interviewers may ask to better understand your merits and skills that enable you to succeed in roles requiring Redux knowledge:

  1. What is your strategy for developing and implementing user interface (UI) components using Redux?

  2. What challenges do you think the information technology industry is experiencing?

  3. Tell us about a time when an employer required you to improve the performance and documentation of an organisation’s codebase.

  4. Can you describe some recently developed technological tools that seem compelling to you as a JavaScript developer?

  5. What, in your opinion, is the role of a ReactJS developer in developing modern UI components?

  6. What steps do you follow to monitor and improve frontend performance?

  7. What do you read and watch to be familiar with the latest industry trends?

  8. What are Reducers in Redux?

  9. Do you think there is a difference between state and props?

  10. What are the differences between Java and JavaScript?

Redux Interview Questions And Example Answers

Here are five questions and example answers to help you prepare your own responses for a Redux interview:

Can you explain Redux and its association with JavaScript?

Interviewers may ask this question to evaluate your understanding of Redux in JavaScript. In the response, you can discuss Redux as a state management tool and explain how it helps programmers to work with data easily. To give an impressive answer, you may also briefly define Redux and say why developers use it.

Example answer: ‘Redux is an open-source JavaScript library that developers use to manage the application state and keep it in a single store. This store is a JavaScript object. Redux focuses on a single source of truth for the state of applications. For instance, the user interface state for which the tab is active and data state like the user profile information. It is a robust state management tool, as it allows developers to access application data without having to send state or props to another component.

There are several reasons why developers use Redux, especially when they work with huge amounts of application state that they need in several places in the application. Redux may be helpful when the codebase of an application has a medium or a large size. Developers often use it when working with big applications that have complex nested user interfaces. It helps them to write JavaScript applications that work uniformly across clients and servers. Developers also utilise this predictable state container to perform server-side rendering and easily maintain the code.’

Can you explain the components of Redux?

With this question, recruiters may assess if you know about the aspects of Redux. An appealing answer can include the different components of Redux and their functions. Consider explaining the components with the help of examples.

Example answer: ‘The Store, Action and Reducer are the three main components of Redux. The Store contains the application state and allows developers to access the state. With the Store, developers can also update the state. Actions are payloads of information that developers use to pass data from application to the Store. The Action is an object that defines what happens in an application. With the Reducer, developers specify how the state of an application changes with regard to Actions that developers send to the Store.

For example, a person goes to a restaurant to eat some food. This intention is an Action in Redux, the food server is the Reducer, the food order is the application state and the kitchen is the Store. Just like all the food is in the kitchen, the application state is in the Store. A person receives the food only when they place the order, just like in Redux, where developers define an Action to modify the application state. The server ensures food delivery. Similarly, in Redux, the developer conveys the Action to the Reducer, which returns a new state.’

What are the advantages of Redux?

A correct answer to this question may help hiring managers determine if you know about the pros of Redux. You may mention how Redux enables easy state transfer between the components and why developers choose to use it. An appealing answer to this question can focus on notable advantages of Redux, including state management, performance and debugging.

Example answer: ‘Redux has several advantages, such as the centralised state management system, storing long-term data and excellent community support. In Redux, a state is always predictable, which simplifies its maintenance. Developers can log behaviour and status to efficiently debug and test codes. Redux stores the state of an application on local storage, which offers persistence in the application state. Its centralised state management system makes it easier to work with big and complex applications. Developers can use Redux to store long-term data that users may require to navigate applications.

Redux has a sizeable community of users. If a developer is new to Redux, they can get help with following the best practices, using the program and understanding its various functions. Redux also has different extensions that allow developers to simplify their code logic.’

What are the major features of Redux DevTools?

Your answer to this question may help interviewers to see if you know about the debugging platform for Redux applications. You can mention how the platform allows developers to perform time-travel and live editing. Keep your answer brief while explaining the different features of Redux DevTools.

Example answer: ‘Redux DevTools offer developers an easy way to inspect each state and action payload. With Redux DevTools, it becomes effortless for developers to go back in time by cancelling actions. This can allow them to re-evaluate each staged action by modifying the reducer code. Developers may install Redux DevTools as a package and integrate it into applications or use it as a browser extension.’

What is functional programming?

This question allows interviewers to assess your enthusiasm for programming and determine how well you understand it. Functional programming has an association with JavaScript, which offers the Redux library, so preparing for this question may prove advantageous. To give an appealing answer, you can share some history regarding functional programming and its relationship with JavaScript. You can also include examples of functional programming languages and features of JavaScript that support them.

Example answer: ‘Functional programming, which is one of the important concepts of JavaScript, focuses on developing programs that utilise mathematical functions. It has been part of programming languages like Lisp, Haskell, Scala and Clojure since the 1950s. There are several JavaScript features that support functional programming, such as higher-order functions, functions as arguments or values and first-class functions.’