Top front-end developer interview questions you need to know

No matter what stage of your career you’re in, job interviews never lose that intimidation factor. Sure, overpreparation is not always a good thing, but underpreparing and being unsure of what to expect in your interview is far worse—you’ll be caught looking like a deer in headlights when the hiring manager starts asking you those high-level questions.

Going into an interview, you can typically expect a mix of questions, with a balance of technical trivia and questions that help the hiring manager get a better idea of your individual workflow, expertise and value to a development team. You can expect the interview to touch on a few common technologies and elements of the role, including programming, testing and coding. JavaScript is one of the most important skills a front-end developer needs to improve their desirability in the job pool, as well as HTML and CSS. 

Ready to find your next front-end role? Seen by Indeed can help you find your next great opportunity in tech.

So how do you strike the balance of anticipating questions without sounding like an overrehearsed robot? We’ve compiled a list of some of the questions you can expect to face to help you get in the zone.

The four types of front-end developer interview questions

An average interview for a front-end position might vary from company to company, but you can typically expect the same type of questions. A hiring manager will want to evaluate your skills in four main areas, including your general front-end knowledge, your HTML and CSS skillset, your knowledge in JavaScript, and your skillset as it relates to performance, networks and testing abilities. 

General questions

The general questions section of the interview will be an opportunity for the interviewer to better understand how you’ve adjusted to the evolving state of front-end development. This will be your chance to go into depth about your workflow and the precautions you take working in the front-end.

Take this opportunity to reiterate your knowledge of current front-end tools, as well as define your understanding of the role as a whole. Be confident in your definitions (e.g., Model-View-Controller, Document Object Models and Web Content Accessibility Guidelines) and approach to common front-end duties, including how to fix browser-specific styling issues and balancing conflicting views on a development team.

Sample questions:

  • Explain your day-to-day workflow. What steps do you take to ensure your web design or app is user-friendly?
  • What steps would you take to approach fixing browser-specific styling issues?
  • Can you explain your techniques for handling issues with front-end security?
  • What steps would you take to work on decreasing page load times?
  • How do you handle conflict or disagreements with a project collaborator?

JavaScript questions

Hiring managers expect front-end developers to know JavaScript inside and out. You’ll likely be quizzed on your experience with specific concepts, such as synchronous and asynchronous programming. (Synchronous programming is when the code is executed sequentially from top-to-bottom, and asynchronous programming means the engine runs in an event loop.) Ensure you’re able to thoroughly explain what blocking and event handling means, as well as performance implications.

You might face questions about classical inheritance and prototypal inheritance, as well as the appropriate times to use either. A good rule of thumb is that classical inheritance is almost never preferred; prototypal inheritance (whether it be delegation, concatenative or functional) is preferred when you need to compose objects from multiple sources.

Brush up on various JavaScript concepts, including event capturing, event bubbling, event delegation and high-order functions. Prepare to go into depth in your explanation of how you debug JavaScript code.

Sample questions:

  • What is asynchronous programming and why is it important in JavaScript?
  • What are two programming paradigms that are important for JavaScript app developers?
  • What is the difference between classical inheritance and prototypal inheritance? When is it appropriate to use either?
  • What is a closure and how would you use one?
  • What is your process for debugging JavaScript code?

HTML and CSS questions

HTML and CSS are the bread and butter of a website developer, and you’ll be expected to prove your knowledge and skill in both during your interview. 

You should be well versed in the newest developments in HTML. HTML5 should be your focus, specifically the addition of the newly implemented multimedia elements. A fundamental understanding of the differences between XHTML and HTML is also important, regardless of whether or not XHTML is something you traditionally use. Be prepared to explain semantic markup, tag attributes and accessibility best practices.

That being said, quizzing your knowledge of CSS can take up a significant portion of the question portion of the interview, so we recommend you brush up on your CSS vocabulary and best practices. It’s expected that you’re aware of the basics, including responsive design, adaptive design and layouts. You should be able to confidently describe a CSS float and a Grid System, as well as be able to use these concepts to explain how to identify and fix browser-specific styling and incompatibility issues.

Sample questions:

  • What are the building blocks of HTML5?
  • Can you explain the concept of a CSS float and provide an example of its usage?
  • What’s the difference between “resetting” and “normalizing” CSS? Which do you prefer and why?
  • What are the pros and cons of using CSS preprocessors?
  • How would you approach fixing browser-specific styling issues?

Performance, network and testing questions

Performance, network and testing make up the majority of the day-to-day functions of a front-end developer. You will likely be quizzed on your high-level understanding of general testing best practices and how to conduct different types of tests, as well as the pros and cons of each.

The topic of functional programming and object-oriented programming will probably surface during the interview, so have a good understanding of the benefits and drawbacks of each. As you know, object-oriented programming is typically easier to understand but falls short in its dependence on a shared state. Functional programming, on the other hand, radically simplifies applications and eliminates bugs caused by multiple functions competing for the same resource, but is notoriously less readable and has a steeper learning curve. 

Your understanding of two-way data binding and one-way data flow is likely to come up as well. Two-way data binding is when the UI fields are bound to model data dynamically, meaning when a UI field changes, the model data changes with it. One-way data flow, on the other hand, is when the model is the single source of truth, where the data always flows from point A to point B. In a one-way data flow, changes to an app’s state can only come from the model.

Sample questions:

  • What tools would you use to test your code’s functionality?
  • What are the pros and cons of functional programming vs. object-oriented programming?
  • What tools would you use to find a performance bug in your code?
  • What are HTTP methods? List and explain all HTTP methods that you know.
  • What is a CDN and what is the benefit of using one?
Approaching your front-end developer interview with confidence

Hiring managers tend to stick with higher-level questions as opposed to definition-based questions, as these not only weed out less experienced developers, but also help them appropriately gauge your basic knowledge. Remember that this is not a comprehensive list of every question you’re likely to face in your interview, and it’s just as important to polish your portfolio and prepare for the coding test, as these elements can also make or break your chances at landing that front-end role. 

A lot rides on your success in your front-end interview, but don’t let that intimidate you. Knowing exactly what you can expect in the interview and taking time to hone your skills can take the uneasiness out of the process, allowing you to sell yourself as the competent and valuable front-end developer you are.