20 Web Developer Interview Questions to Ask at Job Interviews

The Internet is a tight crowd these days. At the moment, the world wide web hosts over 1.74 billion websites. Creating web pages and applications people will enjoy reading and come back to is not easy, especially when visitors choose whether they like the website in the first 50 milliseconds of using it. The success of a web-based project largely depends on the proficiency of the front-end web developer you hire to build it. That’s why business owners should take the process of interviewing candidates seriously.

In this post, we will take a look at 20 technical and non-technical web developer interview questions that will let you quickly and unfailingly determine whether a person in front of you is the right fit for the team.

10 Non-Technical Interview Questions For Web Developers

If you are not skilled at coding, assessing a candidate’s technical proficiency is next to impossible. Other than asking for a CV and web developer portfolio samples, it’s better to get to know your future web developer by asking a few non-technical questions.

Even though you will not be able to see how skilled an entry-level web developer is, the following web development interview questions are jam-packed with insights on the candidate’s excitement and readiness to work in a team.

1. Which blogs, newsletters, or websites you follow?

This open-ended question gives business owners and talent managers an understanding of how deeply a candidate is immersed in the field.

At the end of the day, rather than hiring a programmer who writes code to make living, you want to find a professional who’s excited about building new projects, following trends, and improving.

2. Are you a loner or a team worker?

This question is a way to find candidates that fit your project’s culture. Some team managers look for independent self-starters who don’t ask many web developer interview questions and are fully focused on walking the walk, not just talking the talk.

On the other hand, there are business owners who prefer a dynamic, discussion-based working environment. If that’s the case for you, it’s better to look for a developer who enjoys brainstorming, feedback sessions, and peer-to-peer communication.

3. Are you comfortable with writing HTML from scratch?

Contrary to what most web developer resume samples say, recently, it’s not that easy to find a programmer who can write clean HTML code without using third-party tools.

Although coding from scratch isn’t a skill a modern web programmer uses in all daily tasks, you want to make sure a candidate is independent and doesn’t always need assistive technologies to build web projects.

What are the ways to test a developer’s HTML proficiency? The easiest one is to ask a candidate to write a schema for an imaginary website. Watch out missing tags and attributes in the code a developer turns in.

4. What do you know about W3C?

W3C Standards are practically the bible of web development. They define the requirements for rendering, working on web applications, and improving the accessibility of web pages.

If a candidate has no idea about these principles, chances are, this junior web developer doesn’t spend much time following the latest programming trends. That puts your future projects at risk of outdated infrastructure  – better move on and look for a new developer.

5. Which skills are you looking forward to improving at work?

This question helps align the candidate’s and manager’s expectations. For example, if a programmer wants to become a Big Data or Machine Learning expert, it’s likely that web development is just a stepping stone in the candidate’s career.

Business owners would benefit times more from working with a professional who’s fully invested in building web applications and sees himself becoming a professional in the field.

6. Which websites would you classify as “well-developed” and why?

This question provides business owners with two important insights:

• Understanding which practices a developer holds as standards and ensuring they align with your expectations.
• Ensuring that a developer is constantly on the lookout for inspiration, fresh thought, and improvement helps filter enthusiastic developers from reluctant coders.

7. Understanding abbreviations

Although most developers aren’t fond of textbook theory questions, missing out on the basics is a poster characteristic of an amateur programmer.

When asking a programmer to tell what tech abbreviations stand for, don’t go in too deep. Here are a few must-know concepts you can ask a candidate to decipher.

• ALGOL – algorithmic language.
• CLI – Command Line Interface
• HTML – HyperText Markup Language
• SPA – single-page application
• CSS – cascading style sheets.

8. Which browser do you use?

Ideally, you want to find a candidate who answers this question with an “all” or “a lot”. While it’s normal to have favorites and personal preferences, a programmer should be well aware of the details of cross-browser compatibility.

Bonus tip: when discussing cross-browser optimization, find out if a candidate has installed any toolbars (spoiler: “yes” is the answer you are looking for).

9. Let me know how excited you are about the following tasks:

Ask the candidate to grade his desire to be involved in work-related processes from 1 to 5 (or on a different scale). This way, you will have a clear understanding of what tasks a future hire wants and doesn’t want to be a part of.

Here are a few examples of processes an interview can present to the candidate:

• Writing front-end code.
• Writing back-end code.
• Planning and strategizing.
• Providing clients or end-users with tech support.
• Optimize the project for different browsers/devices
• Design-related decision-making.

10. What is the scale of your preferred projects?

When looking for a full-stack web developer, aim to find a professional whose working experience is the closest to the project you are building.

For example, if you are envisioning a large-scale platform, an ideal candidate should know how to handle high-traffic projects.

On the other hand, developers experienced in building small-scale products will not struggle in setting up Apache or optimizing SQL queries.

To find out what other behavioral and problem-solving web developer interview questions show the strengths and weaknesses of a candidate at an interview take a look at our full guide on software developer interview questions.

10 Technical Web Development Interview Questions

After throwing a couple of ice-breaking open-ended questions into the mix, it’s time to move on to the substantial part of the interview – technical skills assessment. Here are the questions you can ask a middle-level programmer at a web developer job interview:

1. Do you use AJAX in your projects? If so, why?

If a candidate you are interviewing isn’t an excellent communication, you might be getting a smirk or a shrug at this question. While, on its own, the question is basic, it does a great job at testing a programmer’s skills of explaining tech terms in simple language, as well as shows how well-versed a developer is in basics.

AJAX stands for Asynchronous JavaScript and XML. The technology is used to create faster interactive web applications and does a great job at improving the application speed.

2. Define the difference between functional and non-functional requirements

Functional requirements are those that directly relate to the product’s features (processes, pages, etc). On the other hand, non-functional requirements are applicable to a system as a whole, establishing the benchmarks for performance, security, accessibility, or scalability.

3. What is your experience in SQL?

To be clear, using SQL isn’t a must-have for full time and remote web developer jobs. However, in most cases, programmers will be handling databases in multiple work assignments – that’s why you should give massive bonus points to a web development candidate with solid ground in SQL.

4. Describe the function principle of the A* algorithm

In web development, the algorithm is used to traverse graphs and find paths. Developers run the algorithm to estimate the cost of reaching node B starting from node A. To group nodes in the queue and assign an estimate to each of them, the A* algorithm uses a formula:

f(n) = g(n) + h(n)

In the formula, g(n) is the cost of reaching the node in question, h(n) is a heuristic function, and f(n) expresses the node with the lowest estimated cost.

The algorithm finishes its path when the final node is expanded and is denoted as f(n).

5. Define and describe CORS

CORS (short for cross-origin resource sharing) is a tool that allows developers to request resources from a different domain. It’s a powerful way to fuel the exchange of resources that don’t share origins.

CORS supports HTML5 and implements XML HttpRequest to access domain directories.

CORS opens access to origins by assigning new HTTP headers to them. Other than standard GET/POST tags, the browsers need to use HTTP OPTIONS. After receiving a request, a server shares all available methods with the client.

6. What is long polling?

Long polling is one of the most popular web application development patterns. It emulates sending data to establish a connection between the server and the client. Once both are active, the actual data sending request is sent and the exchange is complete.

After closing an exchange, a client generates an exchange from scratch, reopening the loop.

Make sure a candidate says a thing or two about the drawbacks of long polling. Here are a few considerations a freelance web developer should mention when answering the question:

• There’s no way to tell a long polling request apart from other HTTP requests. That’s why long polling tends to abuse system resources leading to connection timeouts.
• The maximum number of connections for long polling varies from browser to browser. That means that, on some clients, the app can be considerably slower than on others.

A good way to continue the discussion on long polling is by asking a candidate to suggest an alternative pattern. A developer should suggest using WebSocket instead since it increases the number of server-client interactions and improves the web application’s performance.

Another way to bypass long polling is to use Server-sent DOM events instead. Although switching to this method increases the number of interactions, it’s not supported by some common browsers, such as Internet Explorer.

7. Describe the difference between stateless and stateful protocols

Answer:

• A stateless communication protocol approaches requests as independent transactions. Thus, it doesn’t require session retention on the server’s or the responder’s behalf. HTTP is an example of a stateless protocol since it doesn’t store user information when handling requests.
• A stateful protocol is characterized by the fixed state of the responder meaning that its identity, session data, status, and other properties don’t change across a large number of requests. There are different ways for servers to implement stateful protocols – the most common ones are custom headers, cookies, or forms.

8. Describe the difference between POST and GET

Before digging deeper into the differences, a candidate should mention that POST and GET are methods used to process HTTP requests.

The primary objective of GET is downloading data while POST uploads data. However, it’s worth noting that you can use GET for data uploading, as well as to download with POST.

The differences between GET/POST are outlined in the table below:

9. Why do developers prefer using HTTP/2 instead of HTTP 1,1?

Using HTTP/2 improves the performance of a web page or a web application. Here’s how the protocol helps web developers decrease latency:

• Implements server push
• Compresses the contents of HTTP headers
• Prioritizes requests
• Supports parallel element loading without terminating TCP connection.
• Doesn’t have the head-of-line blocking problem that challenged web developers in the case of HTTP1/1.

10. What is MIME?

MIME is short for Multipurpose Internet Mail Extensions. By definition, MIME is considered a standard classification of file formats used for the web.

Web developers can take a look at specific MIME types browser clients recommend using to improve the project’s performance and speed up file transfer. When it comes to MIME file naming, all files have a slash-separated type and subtype. For example, in a filename application/zip, “application” is a file-type and “zip” is a subtype that specifies the nature of data.

If you want to ask web developers a few in-depth questions on a specific programming language, take a look at the guides we have written:

• Top 30 PHP interview questions
• Top Elixir interview questions.

Hiring web developers isn’t easy – there are a lot of technologies candidates applying for junior web developer jobs need to have a grasp of. That’s why most talent managers don’t ask in-depth technical web developer interview questions and try to get a general understanding of whether a candidate is passionate about his work and excited to improve.

Finding the right fit for your web development team abroad is even harder since more challenges come with the language barrier, time zone, and cultural differences. That’s why business owners often hire local staffing agencies or employers of record to help build and manage a global software development office abroad.

If you are eager to build a high-performing team abroad, find out how Bridge can help hire top-notch web developers. To see the benefits of onboarding developers in Mexico, Argentina, or Ukraine, use our web developer salary calculator to calculate the cost of maintaining your global team.

If you have questions about setting up a global office, don’t hesitate to drop us a note!