Front End Developer is one of the most sought-after roles in the IT job market. Companies look for professionals who can build modern, responsive and intuitive interfaces using technologies such as HTML, CSS, JavaScript and frameworks like React, Angular and Vue.js.
During the interview, besides technical skills, companies assess communication, problem solving, teamwork and knowledge of web development best practices.
Who is the Front End Developer?
The Front End Developer handles the visible part of a website or application, turning designs and business requirements into interfaces that users can actually use.
- Building responsive web interfaces.
- Implementing UI components.
- Integrating with APIs and backend services.
- Optimizing performance.
- Improving the user experience (UX).
Most common technical questions
1. What is the difference between HTML, CSS and JavaScript?
This is one of the most common questions in a Front End Developer interview.
- HTML: page structure.
- CSS: style and layout.
- JavaScript: logic and interactivity.
Practical case
On an e-commerce page:
- HTML creates the "Add to Cart" button.
- CSS defines its colours and size.
- JavaScript updates the number of products in the cart after the click.
2. What is the DOM?
The DOM (Document Object Model) represents the structure of a web page as a tree of elements that JavaScript can modify dynamically.
Practical case
If a user clicks "Show Details", JavaScript uses the DOM to display a hidden section without reloading the page.
3. Difference between let, const and var
| Keyword | Scope | Reassignable |
|---|---|---|
| var | Function | Yes |
| let | Block | Yes |
| const | Block | No |
Practical case
For a configuration value that must not change, such as an API URL, it is better to use const.
4. What is Responsive Design?
It is the technique that lets a website adapt automatically to smartphones, tablets and desktops.
Practical case
A horizontal menu on desktop can turn into a hamburger menu on mobile devices.
5. What are REST APIs?
REST APIs let the frontend communicate with the backend through HTTP requests.
- GET: retrieve data.
- POST: create data.
- PUT: update data.
- DELETE: delete data.
Practical case
A weather app retrieves weather information through a GET request to an external service.
6. Do you have experience with React, Angular or Vue?
Many recruiters want to hear about concrete experience with the most widely used frameworks.
Sample answer
I built a company dashboard in React using reusable components, React Router for navigation and Redux for global state management.
7. How would you optimize a website's performance?
- Lazy loading images.
- Minifying CSS and JavaScript.
- Code splitting.
- Caching resources.
- Optimizing API requests.
Practical case
On a site with hundreds of products, lazy loading images significantly improves page load times.
Problem-solving questions
Many companies set practical tests or live coding.
Example 1
Build a component that displays a list of users fetched from an API.
Example 2
Find and fix a bug in a JavaScript application.
Example 3
Create a responsive card using Flexbox or CSS Grid.
Behavioural questions
Tell me about a project you are proud of
Use the STAR method:
- Situation: describe the context.
- Task: explain the goal.
- Action: describe what you did.
- Result: share the results achieved.
Practical case
I built an internal portal that cut request handling time by 40% thanks to a new, more intuitive and faster React interface.
How do you handle criticism of your code?
Companies value candidates who are open to feedback and focused on continuous improvement.
Sample answer
I see code reviews as an opportunity to learn new solutions and keep the quality of the software high.
How do you handle tight deadlines?
Sample answer
I prioritise the most important activities, flag any risks to the team and break the work into manageable tasks to meet the deadline without compromising quality.
Mistakes to avoid
- Not knowing the projects in your own portfolio.
- Underestimating the basics of HTML, CSS and JavaScript.
- Not researching the company.
- Not asking the recruiter any questions.
- Focusing only on frameworks without understanding the fundamental concepts.
Tips for passing the interview
- Review HTML, CSS and advanced JavaScript.
- Study the framework the company requires.
- Update GitHub with your best projects.
- Practise with coding challenges and mock interviews.
- Prepare concrete examples from your experience.
- Show curiosity about new technologies.
- Show you can work in a team.
Conclusion
A Front End Developer interview requires a combination of technical skills, communication and a problem-solving approach. With proper preparation and the ability to make the most of your practical experience, you can stand out from other candidates and significantly increase your chances of being hired.