20+ Best UI Developer Interview Questions

ui developer interview questions

The UI Developer is a fairly new role in the technology organization. If you are interested in trying to secure this role, I’ve provided a list of UI Developer interview questions and answers which can help you prepare for your upcoming interview. The person you interview with will most likely sit on the product development organization or team. They are someone who is going to be part of the product team as a whole, this is basically the team responsible for the development of web or mobile applications that address customer needs. The UI Developer role is a newer one, we’ll go into why it has been created and what some of the benefits to the role are as well.

ui developer interview questions

Why the role has been created

Recently, this role has been created because the demand for high levels of design has increased. Or a better way to describe this is that consumers or customers are expecting UI design to be extremely high class. That means if a designer is constantly tasked with the development of their UI, they might either risk the ability to focus on developing amazing pieces of work or fail to deliver what their front-end and engineering team requires in order to get the job done. That has made a new opportunity exist, the UI developer. This person sits right in between the engineering team and the designer to help translate beautiful pieces of UI into something that the engineering team can pick up very quickly and start creating logic for. As teams become larger, this role becomes more critical as well. Because that person helps bridge the gap between any of the designs currently being worked on as well as prior logic or functionality which might exist inside the application. Without it, the engineering team might be left with a lot of questions and ultimately this slows down their ability to produce great work. Lastly, if that does exist, then there becomes some contention between the designers and the engineering team, which executive leaders in the product management part of the organization always want to avoid.

A helpful video

Before we begin looking at interview questions, I like to provide you the visitor with a video that speaks to the role in question. Ideally this should help you in understanding how to communicate your value of the position to the person you are interviewing with. Hopefully you find the video below helpful before you dig into the interview questions themselves.

UI Developer Interview Questions Table of Contents


1. How would you describe the UI Developer role?

The role of the UI Developer is to help the design and engineering team create a more synergetic relationship. For instance, if the designer isn’t familiar with all of the backend engineering an application, they are going to have a more difficult time changing or evolving parts of the web application. Because of this, they’ll essentially have less time to create wonderful and well-working UI designs that can serve the needs of our customers. The UI Developer, in short, helps turn UI designs into reality by developing the closer to front-end requirements a piece of UI may have.

2. Who is it that you help?

The UI developer helps two people, the backend engineers, and the designer. The reason for this is that the backend engineers and even front-end engineers would be experiencing a lot of friction if they had to guess what the designer was attempting to do with their work, all the while creating the backend engineering logic to meet requirements. It leaves too many open-ended questions that don’t facilitate the creation of great work from either end of the spectrum. In this sense, this services both the engineering department and the design department.

3. Do you need to know a lot of code?

UI Developers do need a healthy understanding of code. Most front-end frameworks should be of knowledge. HTML, HTML5, JavaScript, Ruby on Rails, Jquery, React and many more. This person also needs to have a very good eye for detail as they are going to be dissecting the UI elements and turning them into functioning front-end code for backend engineers to pick up. The eye for detail I would say is more important than the knowledge of a lot of code.

4. What types of code languages should you be familiar with?

HTML, HTML5, JavaScript, Ruby on Rails, Jquery, React, Node, Python, iOS, Swift and a few more.

5. How do you go about understanding the app architecture?

The ways a UI developer can go about understanding the backend architecture is by inspecting a few different parts to the application. The first one would be the tests inside the application. This gives the UI developer a level of insight into what logic the application has and what core functionality is trying to be served to the user. Also, interviewing the engineering department is another way, but can be a bit intrusive sometimes. The other way is to be looking through the models and the controllers of the application to understand the logic in more detail. This should give a general understanding of the architecture behind the application and give the UI Developer a little more knowledge about what to be prepared to do when the designer makes changes or redesigns to the applications UI.

6. Should you use em’s or spans for web application images?

Ideally you would use spans. Sometimes there are restrictions to using other HTML elements as pseudo-elements for UI images but in many cases, the span is the best element to use.

7. How much do you need to know about web accessibility?

Understanding web accessibility is a big part of the UI developer role. Because we want all people, regardless of their potential disabilities to be able to use our products. Being able to translate UI elements into functioning front-end prototypes that are accessible by not only all devices but all handicaps is extremely critical.

8. What are spec sheets?

Spec sheets are informational diagrams or pieces of information provided by the designer that tells engineering departments what they would expect to happen if users clicked or participated in certain events on their designs. This gives engineering teams the ability to reference the intentions of the designer without them being present.

9. What prototyping tools should you use?

There are a variety of prototyping tools that are available on the market today. Some of the favorites of UI Developers would be Proto.io, FramerJS, InvisionApp, Moqups and many more.

10. What is TDD and how does it impact your role as a UI Developer?

TDD refers to Testing Driven Development. This when developers write tests to their code while its in development. UI Developers need to have a firm understanding of this type of engineering as they will be changing the way that tests either pass or fail as part of the application.

11. What is MVC?

MVC stands for Model, View, Controller. This is the main way that most application frameworks have been developed. It's important for UI Developers to understand these frameworks as they often work within the view and controller part of the application. Having a good grasp of MVC theories as a whole is a critical component to success in the position.

ui developer interview questions

12. Do UI Developers work within application views?

Yes, absolutely. UI Developers work within the application views because that is where the UI elements are executed. It is where the front-end designs are essentially accessed by the user. A view is a sort of HTML document that is executed under certain conditions. This is where UI Developers will be spending most of their time.

13. How do you interface with designers about work in progress?

Its important for the UI Developer to interface with designers frequently. There needs to be a high touchpoint between the design and the UI Development phase. Essentially, the UI Developer and the designer need to work in tandem, ensuring that requirements are met and that expectations are managed. The more the UI Developer can be closely integrated with the designer in the design phase, the better off everyone will be.

14. What are some ways you can confirm backend functionality?

Confirming backend functionality is hard to do when interfaces are being changed dramatically. The best thing to do is to make sure the UI Developer is part of the SCRUM and to ensure they are on the daily stand-ups. This is where functionality is often discussed and if something changes, it is brought to the attention of everyone on these events.

15. What front-end frameworks do you know?

jQuery, Rails, HAML, SASS, LESS, React, Redux.

Its important in this question to be really upfront about which frameworks you have experience with. Its okay if you don't have experience with them all, showing that you have experience with some and the desire or passion to learn more will be enough. It can also be helpful if you explain in your off-time that you learn new programming languages and frameworks for fun. This can show future employers that you are always willing to develop yourself further and that they should take a risk on you because of your passion with the space and education you'll receive.

16. What is LESS and SASS?

These are abbreviations for frameworks which compile CSS. I should say that they don’t just compile CSS but also extend their functionality through uniformity. For instance, if a company has a set of brand colors that they use, LESS and SASS allow those colors to be referenced only one in the CSS and then accessed in the places it needs to be. Meaning, if the company decides it wants to change its colors from black to white, with a one line change, that can happen in all of the places where the color black is referenced.

17. What is HAML?

HAML is a front-end framework for extending HTML documents usually inside Ruby on Rails applications. It's there to make the readability of long HTML files more affordable to engineers. This means, making it easier to read and thus easier to work with. There are a variety of frameworks and extensions like this available on the market to help efficiently increase the readability of code in hopes that it helps engineers manage larger applications more easily.

18. If you create a button should you use a link or a button class?

Ideally you should create a button class. Per web accessibility standards, you want to use the button function in HTML whenever you have a button in use. Sometimes, though, you are not able to use a button class if there is extremely unique types of functionality. Only then should you use a link class.

19. What is the hamburger icon?

The hamburger icon refers to a three-lined piece of iconography that opens up top-level navigation for a web site or application. It is a recent UI pattern that has seen some surface of popularity in the past 5 years.

20. What JavaScript libraries would you use for interactive elements in a web application?

Ideally, jQuery is your go to library of choice. jQuery and jQuery animate comes with a variety of animation tools which helps you to build interactive elements within a web application. Any other tools for this job are probably not necessary.

21. Would you choose JavaScript for your UI views?

This is a somewhat loaded question. Ideally, you should use any front-end language that is most efficient for the job. This is called a polyglot approach. Although, you may not be able to do that depending on who and what the application is built with regarding the backend engineering and logic. But with regard to JavaScript, in particular, it is a very lightweight programming language. So it is a great choice if the rest of the application is already built with JavaScript.


The UI Developer role is a fun position to be in, you have the ability to help the whole engineering department build better applications more efficiently. You help the creative people in the product management organization be more creative and you also help the engineer teams manage their time better. You are a critical part of the team. UI Developers can also fail to help the teams they support if they don’t consider both parties, if they are too concerned about the design and not as concerned with helping the engineering team facilitate their requirements, they will make it very difficult for new products to get created. It's important that this roles serves both parties and are part of both the product design process as well as the engineering process. Meaning, they may be part of the explorations and discussions of where product designs need to take the product as well as the discussions that happen about the engineering after the design has been confirmed as ready for development by the executive team. You’ll be in a very transitional role, going through many parts of the software development team.

Being prepared for the UI Developer interview

Being prepared for your job interview as a UI Developer is pretty simple, the first thing you should know is what products this company has in development or already in the market. You should be able to find this out by looking up the company, understanding what products and solutions they deliver and if its a consumer-driven company, installing the applications yourself. The use of the applications will give you the best knowledge of what their future needs might be with UI Development. This should help you get prepared to answer questions related to specific products, for instance when they ask you how you might be able to improve the UI or code of X product. The other thing that you should have is a portfolio of work. You won’t have the creative UI work in your portfolio, but you should have the application front-end experiences ready to either be accessed or a series of screenshots that you can show. If you can show off at least some web applications and some mobile applications, you’ll have a higher chance of being hired. Any UI Developer with Swift experience is going to be in really high demand.

ui developer interview questions

On all interview questions

If you have any other UI Developer interview questions or answers that you’d like to see listed on this page, please feel free to contact me. With all of these questions and answers it's important that you recognize that they are for practice sessions only. You should come up with your own set of answers to these questions and put together a practice scenario for which you deliver them. Your confidence in the delivery of the answers will go much further than your reiteration of the questions above.

author: patrick algrim
About the author

Patrick Algrim is an experienced executive who has spent a number of years in Silicon Valley hiring and coaching some of the world’s most valuable technology teams. Patrick has been a source for Human Resources and career related insights for Forbes, Glassdoor, Entrepreneur, Recruiter.com, SparkHire, and many more.


Help us by spreading the word