Best interview questions for React.js developers for hire

What if you need a proper React developer? Well, it seems like you are building something and choosing an excellent tool for it. But it is essential to find the right developers that will run your idea. The hiring process is an interesting process not only for recruiters but also for every startup owner who is building their team. In this post, I'll not write about places where you should look for developers. Today's topic is - interview questions for React developers. Otherwise, how did you know if that is the right person for your team?

Before we get into some relevant question samples, it's important to note that a React developer generally has to go through two interviews. HR interview and technical interview with a team leader or a tech-savvy person. I'll separate the questions into two categories: soft skill questions, which the HR manager usually asks, and hard skill questions, which the team leader asks. So let's start with soft skills.

Soft skills questions

What are soft skills?

Non-technical skills related to how developers behave in the work environment are known as soft skills. You can learn more about this term here.

Why should you ask about soft skills first?

Such skills are equally vital to the developer as to any other specialist who works in the team. They include how developers engage with their colleagues, handle challenges, and manage the work process.

Here is a list of questions for a soft skills definition. It is just a list of questions; if I also write explanations to them, the post would be enormously big. So if you need more information about why such questions are used - check the source.

• What is a dream job for you?
• What exactly are your responsibilities in a current job/was in a previous company? What role are you convenient with most?
• What was the most serious issue you resolved at work?
• Is it more comfortable for you to work independently or in a team?
• How do you handle last-minute changes to deadlines?
• How many projects do you work on at a time?

Hard skills questions

You probably already know what hard skills are. But in any case, here is a short reminder. Hard skills are easily quantifiable abilities or skill sets that can be learned via practice, completion of a certain task, education, etc.

The list of questions below isn't limited to all possible questions that can be asked to evaluate the hard skills of a React.js developer. These are one of the most popular ones that we normally ask during tech interviews despite the level of expertise of such a specialist.

• How would you optimize a React application's performance?
  Expected answer: you can use stateless components and React PureComponent, using immutable data structures, multiple Chunk files, or spreading props on DOM elements.

• Can you compare React and Angular?
  Expected answer: React is a library, whereas Angular is a framework. React.js uses the virtual DOM and one-way data binding, while Angular uses the real DOM and two-way data binding. There's also a variation in speed. There is a difference in bundle size: React's is smaller; therefore, it works faster.

• What are the main limitations of React.js?
  Expected answer: some standard functions in React will not be able to leverage state properly, so we'll use ES6 instead. React technology is so quick that it is impossible to document the project properly. Some developers see JSX as a hurdle, particularly new developers, who complain about the learning curve's complexity.

• What occurs throughout a React component's lifecycle?
  Expected answer: the React Components' lifecycle passes through four stages: Initialization, Mounting, Updating, and Unmounting.

• What is Redux?
  Expected answer: library for manipulating data flow in JavaScript. Allows adding a layer to an application where the state is described in a JavaScript object needed for more convenient code writing.

If you thought that it was all you needed, you would be wrong. How would you estimate the developer's skills without knowing his project's background? Or maybe some cases were solved by his knowledge. Here are some other points that should be considered while hiring a React.js developer.

• Recommendations

You can always check recommendations from clients who have worked with the developer you invited to the interview. Client's feedback may be found on LinkedIn profiles and online IT communities. There you may see how productive this developer has been at work, and examine the weaknesses and strengths of the candidate.

• Cases and reviews

It's essential to evaluate past roles and the developer's background in connection to the position for which the candidate is being interviewed. Typically, this information may be found on a candidate's Linkedin profile. A LinkedIn profile might be even more detailed than a resume.

• Number and type of projects

While hiring a developer, the question of the number and the type of projects is critical. The number of projects and their essence will show s the level of the developer's experience, the sorts of tasks they can complete, and the results of their work.

• What other aspects should be considered?

It will help if you ask open-ended questions with no right or wrong answers. For instance, you could ask why pages on a hypothetical website take so long to load. In this case, it would be better if the developer could clearly explain why this problem exists and how to solve it. The developers must think logically and explain their thoughts correctly because they may have to work in a team and explain something to less experienced employees.

So, have you found this post useful? Write your thoughts in the comment below. And if you are a React developer yourself, it would be really useful for the community to learn about your interview experience! I would also like to share with you an article about the process of hiring a React.js developer, hope it will also help some of you.