Web Developer Interview Questions And Answers

1. Explain what are the key responsibilities of a Web Developer?
Answer:

  • Program test and debug all web applications 
  • Design, develop, test and deploy web applications
  • Uploading sites onto a server and registering it with different search engines
  • Coordinate with other designers and programmers to develop web projects
  • Fix bugs, troubleshoot and resolve problems
  • In case of system, failure initiate periodic testing and implement contingency plans
  • Develop appropriate code structures to solve specific tasks
  • Support and assist in the upkeep and maintenance of websites
  • Assume ownership of code throughout staging, development, testing, and production

2. How are you keeping up with the latest developments in web development?
Answer:
In other words, this will determine if your candidate continues to learn to program and makes the effort to stay on top of his skills. You can ask your candidate about their favorite programming-related Twitter accounts and why they like it, for example. If your candidate doesn’t use Twitter, ask which tech publications they read and authors or personalities in the dev world they admire and why.

Web development is always changing, so being curious about the latest trends and forming opinions about them is typically a good sign.

3. What are data- attributes good for?
Answer:
data- attribute is used to assigns custom data to an element. The stored (custom) data can then be used in the page’s JavaScript to create a more engaging user experience.

4. Explain what is long polling?
Answer:
Long polling is a web application development pattern used to emulate pushing data from the server to the client. With long polling, the client requests information from the server in a similar way to a normal poll. However, if the server does not have any information available for the client, instead of sending an empty response, the server holds the request and waits for some information to be available. 

5. What is the advantage of collapsing white space?
Answer:
White spaces are blank sequences of space characters, which is treated as a single space character in HTML. The browser collapses multiple spaces into a single space, so we can indent lines of text without worrying about multiple spaces. This enables us to organize the code into a much more readable format.

6. List some of the new CSS properties introduced with CSS3?
Answer:

The following is a list of new properties added in CSS3:

  • border-radius
  • box-shadow
  • text-shadow
  • text-stroke
  • background-size
  • text-overflow
  • resize
  • transition
  • Also, other features like multiple backgrounds which allow you to have two or more background in the very same selector and flexible box model which ensures that elements behave predictably when the page layout must accommodate different screen sizes and different display devices.

7. What is Logical Topology?
Answer:
Logical topology refers to the mapping of nodes based on the paths taken by actual data in the network. It is similar to signal topology, but here the determining factor is the path of data, not signals. In many cases, logical topology and signal topology are used interchangeably. 

8. What is a Web Server?
Answer:
Web Server is an important component of the presentation tier of the three-tier client-server architecture. It is a computer program that accepts the Http requests and sends the requested data as Http response. The data mainly consist of HTML pages.

There are two types of data:

  • Static Web Server – Static content is the data that is present in the file system in the database server
  • Dynamic Web Server – The program that is run by the webserver generates Dynamic content. It is slower compared to static content. Apache, Microsoft IIS are examples of web servers that are commonly used.

9. What is a pseudo-class?
Answer:
It is a CSS technique that sets the style when an element changes its state. E.g. style changes when mouse hover, different styles for visited or unvisited links, etc.

10. By which mechanism in JavaScript can you detect the operating system on a client machine?
Answer:
The operating system on a client system can be known by using the JavaScript property navigator.appVersion.

The above web developer interview questions and answers will help you to get an understanding of the type of questions you can expect in such interviews. However, if you need to gain expert-level skills to clear the technical round of interviews in any organization, you should enroll in a certification course. Naukri Learning offers you a variety of online web development courses that you can enroll in and get certified to improve your chances of clearing an interview and getting a career boost.

11. What is the first thing you do when assigned a website development project?
Answer:
This is your chance to show them that you understand the business, that you can work independently, that you think about the website from the perspective of a final user, and the client–the goals they want to achieve.

Tell them that you always analyze the project, trying to understand the final goal of a website (sell goods, bring customers to a shop, improve the reputation of the company, convince the visitors of some facts, etc), and plan your development accordingly.

12. How would you use persistent storage on browsers? What options would you use?
Answer:
For HTML browsers, a good choice would be local storage and persistent storage. For non-HTML ones, cookies are the best bet.

13. Explain how you optimize and reduce web application load time?
Answer:
Almost half of all users want a web page to load within two seconds. Ask this question to learn if a candidate is aware of the impact that page load time has on the user experience, and how a web developer should analyze data and track improvements to optimize load time.

What to look for in an answer:
H
ow much importance they place in optimizing web applications

Understanding of tools they can use to analyze website speed
The evidence they have successfully reduced load time
Example: “Although there are numerous techniques a web developer can use in reducing the load time, I always rely on optimizing images, enabling browser caching and minimizing HTTP requests. My go-to tool for evaluating site speed is Google PageSpeed Insights. In one instance, I successfully reduced page load time from 2.1 seconds to .7 seconds by solely enabling browser caching.”

Almost half of all users want a web page to load within two seconds. Ask this question to learn if a candidate is aware of the impact that page load time has on the user experience, and how a web developer should analyze data and track improvements to optimize load time.

14. What is the difference between window.onload and on document ready?
Answer:
The window.onload event will not trigger until every single element on the page has been fully loaded, including CSS, images and/or other assets. The main disadvantage is that it might take a while before any code is actually executed. On the other hand, on document ready executes code as soon as DOM is loaded.

15. How is jQuery different from Javascript?
Answer:
Well, jQuery is not a programming language, but a well-written JavaScript code (a framework). It is a library built with Javascript. Javascript is the core programming language. It is very popular because it abstracts away cross-browser compatibility issues and emphasizes unobtrusive and callback-driven Javascript programming.

16. you describe your workflow when you create a web page or web app?
Answer:
This is a good way to assess how your candidate approaches a basic chunk of work. Do they use snippets to quickly layout a basic HTML page, add a little jQuery and start coding? Or do they use a more in-depth approach such as Bower or Yeoman?

17. What tools do you use to find a performance bug?
Answer:
This will depend on your candidate’s development environment as different programming languages use different profilers and some frameworks have built-in debug tools to find performance issues. (Company)This doesn’t matter too much, but their approach does.

18. How do you take into account SEO, maintainability, UX, performance, and security when you’re building a web application?
Answer:
This is a biggie. The ability to balance and understand these very different factors is a core competency for any web developer. Their response will also indicate which factors they will prioritize when coding. For example, if you are a large financial institution, you may favor security over SEO. If you are an online publication, performance and SEO will be more important for your type of work.

19. What is the trend in website development right now?
Answer:
Fast, reliable, secure. Websites that work well on mobile phones, websites that are simple to navigate and use. Websites that can be easily managed and changed from the back end. And most importantly, websites that are built with a target in mind–websites that actually convert visitors to customers.

You can elaborate on your answer, talking about specific tools and techniques that help you to design trendy websites (AMP, content management systems, HTTPS protocols, cloud hosting, and so on and so forth). 

20. What are two common ways in which you can reduce the load time of a web application?
Answer:

There are quite a lot of ways you can reduce load time:

  • Enable browser caching
  • Optimize images
  • Minify resources
  • Minimize HTTP Requests
  • Reduce redirects

21. What is the difference between position fixed, static, relative and absolute?
Answer:

poste:  static is the default position of an element on the page, and behaves as if its in the “normal flow” of the document structure.
poste: fixed takes the element out of the normal flow, and functions as absolute positioning relative to the viewport – meaning they don’t move when the window is scrolled.
poste:  relative will position the element in the flow, but can be positioned (using top, left, Droit, bottom) relative to its current position in the document.
poste: absolute takes the element out of the flow and can be position relative to its closest non-static positioned ancestor (if none, it uses the window).

22. What is Signal Topology?
Answer:
Signal topology is the mapping of different nodes in a network based on the paths by which the signals pass through. Signal topology generally refers to the actual path that the signals (e.g., electromagnetic, electrical, optical, etc.) take when propagating between nodes. 

23. In Signal Topology which materials we use to connect nodes?
Answer:
Signal topology is the mapping of different nodes in a network based on the paths by which the signals pass through. Signal topology generally refers to the actual path that the signals (e.g., electromagnetic, electrical, optical, etc.) take when propagating between nodes.

24. Who checks whether the authorized person only can access the intranet?
Answer:
An intranet of an organization is accessible to employees of that particular organization only. A software known as the firewall is used to ensure this. Firewall checks whether the authorized person only can access.

25. What is the word from which “Ethernet” is derived?
Answer:
Ethernet, as the name suggests, has been evolved from the ancient term “ether”, meaning the medium through which light propagates.

26. Who & in which year introduced www?
Answer:
The whole idea of www was introduced in 1989 by Sir Tim Berners-Lee, who is considered as the father of the internet. Since then the growth of the internet was rapid. Tim Berners-Lee himself introduced the terms like URL, HTTP. He is currently the chairman of W3C which is the governing body of the web.

27. What’s a DOCTYPE?
Answer:
A doctype associates a markup document (Html or xml) with a DTD. It tells the browser what kind of document and what type of markup to expect. HTML 4.01 has strict, loose (transitional) and frameset DTDs depending on how standard-compliant you want it to be. XHTML also uses the same strict, transitional and frameset DTDs but also needs a specific XHTML namespace declared with. HTML5 does not need any references to a DTD. Another thing to note is that HTML5 encompasses HTML4 AND XHTML1.

28. What is event delegation and how does it work?
Answer:
Event delegation allows us to avoid adding event listeners to specific nodes of the DOM; instead, the event listener is added to one parent. Using event delegation it’s possible to add an event handler to an element, wait for an event to bubble up from a child element and easily determine from which element the event originated. 

29. What web browser do you use?
Answer:
Because web developers should be familiar with all browsers in terms of testing their web projects the best answer here is: All of them.

30. web developer works on a website design. We can see the screen of their computer in the picture. Which tools do you use to analyze website traffic?
Answer:
Tell the interviewers that you understand the importance of traffic analysis. Unless we know how many people came to the website, and what they did there, it makes no sense to have a website.

You can always say that you install Google Analytics on each website you design. If you have any experience with advanced traffic and conversion analyses, using one of the paid trackers, you can mention it in your interview answer.

31. What web browser do you prefer?
Answer:
A good web developer understands it is crucial to design a website that looks good in all browsers (including mobile browsers), and on all screens.

This is exactly what you should focus on in your answer, saying that you prefer one of the browsers (perhaps Chrome for their tools for Web Developers), but design websites that work well with all browsers and screens.

32. What are the web technologies that you are proficient in?
Answer:
As already mentioned, you must have expert skills in three technologies: HTML5, CSS3, and JavaScript. Apart from that, you should be able to have at least some working knowledge of some of the other technologies like popular frameworks, APIs and database management.

33. hat are the responsibilities of a web developer?
Answer:
A web developer should fully understand their role and how they contribute to web design and development. This question will help you find out how a candidate plans to support the team and what tasks they will take ownership of.

What to look for in an answer:
A clear understanding of web development processes
What tasks they emphasize
How they plan to contribute
Example: “A web developer designs, develops, enhances, tests and deploys web applications with an end goal of creating engaging and user-friendly site layout and function. A developer gathers and defines requirements, maintains websites, troubleshoots and fixes bugs, follows best practices and collaborates with other teams.”
Show the answer

34. Explain how you optimize and reduce web application load time?
Answer:
Almost half of all users want a web page to load within two seconds. Ask this question to learn if a candidate is aware of the impact that page load time has on the user experience, and how a web developer should analyze data and track improvements to optimize load time.

What to look for in an answer:
How much importance they place in optimizing web applications
Understanding of tools they can use to analyze website speed
The evidence they have successfully reduced load time
Example: “Although there are numerous techniques a web developer can use in reducing the load time, I always rely on optimizing images, enabling browser caching and minimizing HTTP requests. My go-to tool for evaluating site speed is Google PageSpeed Insights. In one instance, I successfully reduced page load time from 2.1 seconds to .7 seconds by solely enabling browser caching.”

35. What’s the best way to integrate 5 different stylesheets into a website?
Answer:
It usually depends on how the site is laid out. However, in most cases combining the stylesheets into a single one is the best approach. You can use Gulp to do so. 

36. What is your preferred development environment?
Answer:
This question is not about checking if you are perfect for the same environment as the organization works but to measure if you are flexible to work in any environment. So, give them a hint that you are able to adapt to any environment with the core skills that you have. 

37. What are your key responsibilities in your current organization?
Answer:
Are you working in specific development areas? Do you only support the maintenance and upkeep of a website? Or Are you involved in all major steps in development including fixing bugs? Do not leave out any responsibilities which you think can help in leveraging your candidacy for the role

38. What is W3C and why is it important?
Answer:
A web developer should take responsibility for the content they produce, see that it is accessible by all users and follows W3C standards. This question will let you know if a candidate has a working knowledge and respect of W3C.

What to look for in an answer:

  • General knowledge
  • Consideration of standards
  • Specifics on how they adhere to standards
  • Example: “W3C stands for World Wide Consortium and it is an international community that focuses on developing and standardizing the web. As a web developer, enforcing these standards ensures that web content is accessible in all browsers to reach all audiences, as well as optimizes the user experience. For example, using W3C-compliant CSS and XML allows every website to function similarly, but also improves SEO.”

39. What is W3C?
Answer:
W3C stands for World Wide Web Consortium which is the international standard for the World Wide Web. W3C is constantly busy trying to standardize the web and to make it accessible to all users. The company was created in 1994.

40. What’s the difference between standards mode and quirks mode?
Answer:
Quirks mode is a default compatibility mode and may be different from browser to browser, which may result in a lack of consistency in appearance from browser to browser.

41. What are the limitations when serving XHTML pages?
Answer:
The main limitation is the poor browser support of XHTML. Internet Explorer and other user agents cannot parse XHTML as XML. Thus, it is not that extensible language as one might think.

42. How do you organize your JavaScript code?
Answer:
These questions will give you an insight into how your candidate organizes their code. Do they separate JavaScript and HTML, Is the JS broken into logical units and kept in separate files, Do they use a script to concatenate these files into a single bundle? Do they use JS namespaces to avoid cluttering up the global namespace?

43: Describe the difference between cookies, session Storage, and Local Storage?
Answer:
Cookies are small text files that websites place in a browser for tracking or login purposes, and hold a modest amount of data.

Meanwhile, localStorage and sessionStorage are new objects, both of which are storage specifications but vary in scope and duration. Local storage is more secure, and large amounts of data can be stored locally, without affecting website performance. Furthermore, is it permanent? sessionStorage only lasts as long as the duration of the longest open tab.

44. Tell me two common ways in which you can reduce the load time of a web application that you have written?
Answer:
It will be a good idea to optimize images to no higher than screen resolution and save it as a compression level which squeezes the size considerably. Another thing that can be done is to eliminate all JavaScript files to reduce the amount of transferable data

45. What’s the difference between margin and padding?
Answer:
Every block element can be described using the box model – padding is the space between an element’s content and its borders, and the margin is the space between an element’s borders and the next element in the flow.

46. Why would you use anonymous functions?
Answer:
Anonymous functions don’t clutter up the namespace, they fit easily in dynamic environments, provide scoping for variables, and automatically dispose of themselves after single uses with no residue. This makes it particularly suitable for scalable web applications that don’t like to assume anything in their code.

47. What are the benefits of using the Internet?
Answer:

  • The Internet is the fastest media of data communication.
  • Using the internet we can send or receive mails.
  • Using VOIP we can take the benefits of Telecommunication.
  • Using various websites we can read news and latest updates.
  • Can Sale Products.

48. What are the Http methods?
Answer:
Basically 3 methods we use under HTTP methods Get, Post and Head. In the GET method, the client-side information is sent to the browser as parameters. These parameters will be encoded with the URL as name-value pair. In the POST method, the information from the client is sent to the server as part of the message body of the HTTP request. The data can also be encrypted to ensure security. The HEAD method gets only the information about the document, not the document itself. As less data is transferred, the HEAD is much faster than getting.

49. How can you reduce page loading time?
Answer:
These are the following ways you can reduce web page loading time: reduce the image size, remove unnecessary widgets, HTTP compression, placing CSS at the top and script referencing at the bottom or external files, reduce lookups, minimize redirects and caching.

50. What sparked your interest in web development?
Answer:
Did the candidate want to become a web developer at an early age? Are they self-taught? Learning why a candidate chose web development can help determine their level of passion and commitment to the profession.

What to look for in an answer:

  • Enthusiasm
  • Motivation
  • Experience

Example: “As a previous marketing coordinator, I frequently used an online tool to create and customize email campaigns. I found the drag-and-drop feature buggy and discovered that I could achieve the look I was going for if I edited the HTML instead. I became fascinated with the ability a web developer has to be imaginative, artistic and technical while developing a product that benefits and inspires others.”

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