Why this matters:

This technical question is best suited to more junior front end developers and tests their understanding of the CSS language. While the technical knowledge is important, it’s the “why” that’s really important here. The candidate’s reason for using floats can help you determine their approach to styling website—and whether or not they’re a good fit for your company.

What to listen for:

  • Candidates should be able to clearly and concisely describe what the CSS float property is and when it’s appropriate to use.
  • If they mention that they use floats to create their entire website layout, this may be a sign that they’re following outdated practices.

Why this matters:

Ajax stands for asynchronous JavaScript and XML (although in modern usage, JSON may be substituted for XML). Essentially, Ajax is a set of web development tools that enable developers to change parts of a web page in the background without reloading the entire page. It’s a good question to test candidates’ basic understanding of different web programming languages and their depth of knowledge.

What to listen for:

  • Listen for answers that mention advantages like improved interactivity and maintaining Javascript variables and DOM state on a page.
  • Strong answers might also touch upon some of the disadvantages, such as the fact that it’s more difficult to bookmark dynamic pages.

Why this matters:

JavaScript templating is a simple and useful strategy used to separate HTML structures from the JavaScript strings they contain. Since this strategy allows developers to be more efficient, all candidates should ideally have a few libraries that they regularly use and can discuss confidently.

What to listen for:

  • Answers may include libraries like Mustache.js and Handlebars.js.
  • The candidates’ reasoning is ultimately more important than their preferences—for example, Handlebars.js is better suited for performance-critical projects or ones that require block expression.

Why this matters:

Front end developers should always have the end user in mind when developing a new website or web application, so the best candidates will take the user experience (UX) very seriously. What best practices have they applied to previous projects? Have they tested assistive solutions to make sure the website or application is accessible to all potential users?

What to listen for:

  • Look for candidates who have first-hand experience implementing usability and accessibility standards.
  • Top answers may mention performing user testing across various devices, ensuring the site or app worked seamlessly and intuitively no matter how a user engaged with it.

Why this matters:

Front end developers must be able to collaborate with other stakeholders, either on the company or the client side, to create an end product that meets their requirements. But the best developers are also dedicated to their vision and are able to make a case for development decisions they believe in.

What to listen for:

  • Look for candidates that navigated the pushback gracefully, listening to the feedback and explaining their perspective.
  • Great answers may cover how they convinced the stakeholder to try it their way, or how they proposed a compromise that was accepted.

Why this matters:

Since front end developers will often need to work as part of a team to push a project through to completion, pay attention to how your candidates approach collaboration, and be sure to ask follow-up questions to really understand their process and the role they took to move the project forward.

What to listen for:

  • Look for signs that the candidate took charge and motivated the rest of the team.
  • Great answers will show that they asked smart, detailed questions along the way to understand the design and functionality requirements.

Why this matters:

Users often have different preferences when it comes to browsers, so it’s important for your company to provide the same exceptional experience, no matter how they choose to access your website. Browser compatibility can be a pain to troubleshoot, so this question can give you a real insight into a candidate’s patience.

What to listen for:

  • Candidates should demonstrate that they’re dedicated to working through the kinks, no matter how frustrating they may be.
  • A good response will show strong attention to detail and a passion for delivering the best possible user experience to the website’s visitors.

Why this matters:

This question lets you test a candidate’s ambition and their willingness to learn. The development landscape evolves fast, so these traits can help a candidate stay ahead of the curve. Dig a little deeper by asking them why they chose that particular technology. Do they think it will be relevant to their work? Do they want to bring more value to their employer?

What to listen for:

  • Strong answers might mention taking a boot camp in their spare time or following forums and blogs that center around the technology.
  • Ideally, candidates will already be taking steps to master their chosen technology.

Why this matters:

Stack Overflow is an invaluable resource for front end developers, allowing them to source advice and answers to development questions from the wider tech community. This question allows you to test how advanced a candidate’s skills are based on the level of questions they’re viewing and answering—as well as their passion for their field.

What to listen for:

  • Look for signs that the candidate is actively engaged in the community at large and willing to share their expertise with others.
  • If they mention that they’re always looking up answers to simple problems, they might struggle with more complex challenges.