Front-End Developer Interview Questions

With social distancing and Work-From-Home (WFH) concepts getting embraced all over the world, the post-COVID era is set to radicalize the traditional interview process. Online interviews will be the most popular style of vetting job prospects. So does this mean that traveling to an interview location, printing out your resume and references, and getting dressed in your most professional outfit will soon be history?

Definitely not. If you think your online interview will be similar to a FaceTime chat with your friends, think again. Just because an interview doesn’t take place in person, doesn’t mean that it’s going to be informal or casual. In fact, you need to prepare meticulously for this digital face-off, and master the ‘netiquette’ if you’re serious about getting hired.

Like all tech jobs, preparing for the job of a front-end developer includes going through a tech interview. Top companies hire front-end developers to create elegant, convenient, responsive, and interactive interfaces, across multiple platforms and devices.

Anticipating the right questions will help you sail smoothly through your front-end developer job interview. Many aspiring front-end developers are unsure of which interview questions they need to prepare for to ace their job interview. While there are plenty of of practice or mock questions available online, it's hard to choose the most relevant ones to practice with.

Whether you're new to web development or an experienced programmer, this article will help you ‘suit up’ for the most important phase of the hiring process. So, let’s review some of the most common questions you can expect in your front-end developer interview.

In Your Own Words, What Does A Front-End Developer Do?

For a question similar to this one, it’s important to start with the basics. Mention that the front end of a website is the interface that users interact with. The front end includes images, buttons, colors, animations, forms, and typography. A front-end developer is a programmer who writes code for the front end of a website. Their main responsibility is to ensure that the appearance of the website remains similar and uniform across the full range of popular platforms and devices.

Because front end developers are involved with the navigation, layout, and design elements of websites and mobile apps, they must be skilled in HTML, CSS, and JavaScript. Also, since they sometimes work in diverse team compositions, which include back-end developers, designers, and other developers, they should have strong soft skills. These soft skills should include effective communication and team spirit.

Which Basic Technical Skills Are Required To Be A Front-End Developer?

To become a successful front-end developer, you should be knowledgeable in:

• HTML
• CSS
• JavaScript
• JQuery

In addition to these must-have skills, the following skills will take your game a notch higher:

• Experience in any CMS (Content Management System) such as WordPress or Joomla
• Cross-browser testing
• Knowledge of object-oriented programming, like PHP and OOPS
• Knowledge of Search Engine Optimization (SEO)
• Basics knowledge of tools which are used to present web-based information to end-users, like Dreamweaver and Flash

How Would You Ensure That Your Web Design Or App Is User-Friendly And Accessible?

A front-end developer should have a strong command over usability and accessibility while designing experiences for end-users. This question will provide the interviewer with an insight into your knowledge of these standards and web development best practices.

To answer this question, you should talk about your first-hand experience in implementing usability and accessibility standards. Discuss your drive to create a web experience that's accessible to all end users. Talk about ways in which you have implemented usability and accessibility in your previous front-end development projects.

For instance, you can say "I test my web applications on various browsers and devices to verify that the experience is user-friendly. I also utilize familiar screen reading software and other assistive solutions to check it’s accessibility."

What Do You Understand About Coffee Script? How Is It Different From JavaScript?

Coffee Script is a small programming language that compiles into JavaScript, and it’s become popular among front-end developers. Its objective is to improve the JavaScript code by providing a consistent syntax and minimizing the irregular nature of JavaScript language.

There are two basic rules in Coffee Script:

• Whitespace matters: Curly braces do not exist in Coffee Script
• No parentheses: Parentheses is not required by functions that take arguments

In JavaScript, you need to add a semicolon for variables at the end to execute them. Whereas, there is no need to add a semicolon at the end of a statement in Coffee Script.

If you can include any of these specifics in your response, you’ll solidify your expertise as a skilled front-end developer.

Are there any advantages of using Coffee Script over JavaScript?

You’ll want to remember that Coffee Script lets you execute your program with much less code compared to JavaScript. You might want to explain why this makes your code more readable for other front-end developers.

Next, it consists of many light features like ‘Ruby String Interpolation’ and Python-style list comprehension. Additionally, Coffee Script makes day-to-day tasks much simpler to perform in comparison to JavaScript. It can also make an already well-written JavaScript code more readable.

All of these features will become invaluable in your front-end development work, regardless of which company you’re interviewing with.

What is the use of clone-function in Coffee Script?

Front-end developer interviews often get technical, so be prepared to respond with specifics.

Clone function can be used to create an entirely new object in Coffee Script using the following steps:

• Clone function creates a new object as the source object
• It copies all attributes from the source object to the new object
• It repeats the steps of copying attributes from the source object for all sub-objects

While you might not get into the fine details during your interview, displaying some of this knowledge could indicate to your future employer that you’ll be a knowledgeable addition to the front-end development team.

Explain the concept of a CSS float. When would you use it?

This question determines your technical understanding of a simple CSS element: a crucial aspect of front-end development code. This technical question allows the interviewer to gauge your knowledge of CSS.

While answering this question, begin by providing a clear definition of CSS float, and why it’s favored by front-end developers. Then move on to providing some examples of how you can incorporate CSS float in your code. For instance, you can state that CSS float instructs the browser to place a particular element to the right or left side of a container. You can also mention that you use floats while developing a page that resizes itself dynamically to the user resolution.

Basically, CSS Float is used when you want an element of your web page to be moved right or left while making other elements work around it.

What is the difference between a GET request and POST request?

It wouldn’t be a true front-end developer interview without some technical coding questions.

Normally, a GET request is used for functions such as when an AJAX (Asynchronous JavaScript and XML) calls to an API (Application Programming Interface). GET requests' security is generally limited and the requests are viewable by the user in the URL.

On the other hand, a POST request comprises of two steps and can’t be viewed by a user. As a result, POST requests are more secure. Also, a POST request is typically used to store data in a database or submit data through a form.

If you have previous experience, you might want to describe how you’ve used these requests in front-end development projects.

What’s the difference between cookies, session storage, and local storage?

As a front-end developer, you probably already know these definitions well. Explain them in a way that shows your interviewer you’re a strong communicator.

A cookie can be described as a small file consisting of letters and numbers that can be downloaded to a system when someone accesses a website. Cookies unlock a computer's memory and allow the source website to identify users when they come back to the page.

The local storage and session storage properties save key pairs or value pairs in a web browser. In a session storage object, data is stored on the client’s side, just for a single session. Thereafter, the data is deleted once the browser tab is closed.

A local storage object stores data without a time limit. Even when the browser is closed, the data will not be deleted. It will still be available the next time you visit the browser after a day, a week, or even a year.

If time permits, you can even describe how these different terms work in action, and how you take them into account while performing front-end development work.

What are some ways to enhance page performance?

Page performance is a key metric for front-end developers. It can be increased by incorporating some of the following methods.

• Cleaning the HTML document.
• Using sprites, compressed images, and smaller images.
• Adding JavaScript at the bottom of the page.
• Reducing external HTTP requests.
• Minifying CSS, JavaScript, HTML.
• Using CDN and Caching.

With that, we’ve wrapped up our guide to acing your front-end developer interview. By being prepared to answer variations of these ten questions, you will be one step ahead of your competition during the interview process.

If you read these questions and found yourself second guessing your knowledge, you should consider our Software Engineering course. It’s designed to give you all the technical skills and interview prep required to land your dream job. Or, if you’d just like a bit more guidance on how to succeed as a front-end developer for a company you’ll love, our blog is full of useful articles to help you do just that.