Frontend Interview Handbook Book [2024]

20 min readApr 15, 2024

I don’t know about you, but when it comes to listing some of my favorite things to do, studying for frontend interviews isn’t one of them. However, without proper frontend interview prep, you won’t be able to put your best foot forward in securing your dream job.

Purpose of This Handbook

This guidebook is designed to assist busy engineers in navigating the complexities of preparing for and acing frontend interviews. It will provide you with all the tools you need to succeed and thrive. The primary goal is to help engineers land their dream jobs, but more importantly, to build a community of frontend developers who can share their own tips on succeeding in a fast-changing industry.

A lot of time and effort has been invested in building this guidebook, which is available completely for free on frontendlead.com. If you find it helpful, please consider sharing it with friends and family.

Studying for frontend interviews can be quite challenging. Unlike general software engineering interviews that focus heavily on algorithmic questions, frontend interviews tend to focus more on real-world domain-specific questions related to HTML, CSS, JavaScript, and more.

This guidebook will provide you with insights into everything you need to know to ace any frontend interviews. Feel free to click on a section below so you can jump straight into it.

Here is a breakdown of what this guidebook will cover:

You can find a easier to read version of the guide book here.

Understanding these components and preparing for each can significantly enhance your performance in frontend interviews. Remember, each company might have variations in their interview process, so it’s advisable to inquire about the format and stages from HR beforehand to tailor your preparation effectively.

Role and Skills of a Front-End Developer

The role of a front-end developer is really important in the world of web development. They focus on creating the parts of websites and web apps that users see and interact with. Using coding languages like HTML, CSS, and JavaScript, front-end developers make sure that these interfaces work well and look good on all sorts of devices and web browsers.

Here’s what front-end developers typically do:

Layout Development: They take design files from tools like Adobe XD, Sketch, or Figma and turn them into functioning web pages using HTML and CSS.
Interactivity: Developers add interactive elements to websites using JavaScript and popular frameworks like React, Angular, or Vue.js to make the site more engaging for users.
Optimization: They work on making websites load quickly and run smoothly on all devices, ensuring a good user experience no matter where it’s accessed from.
Testing and Debugging: Developers are always testing their sites to find and fix bugs, making sure everything works as intended without any glitches.
Collaboration: Front-end developers often work closely with UX designers, back-end developers, and others to make sure the site meets all technical and user needs.

Skills that are essential for a front-end developer include:

HTML/CSS: These are the core tools for building and styling web pages.
JavaScript: This is essential for making web pages interactive. Knowing how to use frameworks like React can really enhance a developer’s ability to build complex features.
Responsive Design: They need to design sites that work well on both desktops and mobile devices, adapting the layout to different screen sizes.
Version Control/Git: This helps in keeping track of changes made to the codebase and collaborating with other developers.
Testing/Debugging: Skills in testing help ensure the software runs smoothly, using tools and frameworks like Jest to find and fix issues.
Browser Tools: Knowing how to use browser developer tools can help fine-tune the appearance and functionality of a website.
Web Performance: Techniques like optimizing images and leveraging browser caching are crucial for making websites faster and more efficient.

As technology keeps evolving, the role of front-end developers is growing and changing, reflecting just how dynamic the field of web development is.

To get a more comprehensive look on the average salary for frontend developers, you can visit our free article here.

Whats the average salary for frontend developers in the US?

In the United States, what front-end developers earn can really vary depending on their experience, where they work, and who they work for. In big tech cities like San Francisco, Seattle, and New York, the salary and benefits package can be pretty impressive.

Here’s a breakdown of what these packages typically include:

Base Salary: Most front-end developers start with a median annual salary of about $153,000. This can climb up to $210,000, and the very top earners can make around $270,000 a year.
Stock Options: Both startups and big established companies often offer stock options. The value of these can vary a lot, depending on how the company’s doing and the overall market. For example, big tech companies (like the ones in FAANG — Facebook, Apple, Amazon, Netflix, Google) might offer something called Restricted Stock Units (RSUs) that could be worth between $50,000 and $200,000 every year.
Bonuses: To attract the best talent, especially in competitive areas, companies offer signing bonuses ranging from $15,000 to $60,000. There are also relocation bonuses that can be anywhere from $5,000 to more than $20,000, depending on how far you’re moving and the company’s policy.
Perks: The benefits don’t stop at money. Many companies also offer great health coverage, retirement plans where the company might match your contributions, programs to help you stay well, and funds for your professional growth. Plus, you might get free meals and help with your travel costs. After COVID-19, it’s also become common for companies to give out money to help set up your home office.

When you add all these up, the total compensation for a front-end developer in a tech hub can easily exceed $250,000 a year. Understanding all the parts of your compensation package is really important. It helps you see the full picture of what you’re earning and the benefits you’re getting, which is super useful when you’re thinking about job offers or planning your career.

For a deeper look into what front-end developers typically earn, you might want to check out this free article.

Understanding the Frontend Interview Process

Navigating the frontend interview process can sometimes feel overwhelming. This guide aims to simplify and explain the different stages you’ll face when applying for a frontend developer job, especially at tech-focused companies. We’ll walk through each part of the interview process, from the first screening to the technical and behavior tests, all the way to discussing your job offer. This way, you’ll know what to expect and how to prepare to do your best.

Here’s a breakdown of the interview stages:

Recruiter Screen: This first step checks if you’re a good fit for the job and the company’s culture.
Technical Phone Screen: Here, you’ll solve coding problems to show your skills.
Take Home Challenge: You’ll work on a project that tests your coding and problem-solving abilities.
On-Site Technical Rounds: Expect deeper technical questions and challenges.
On-Site Behavioral Rounds: These focus on your soft skills, like how you’ve handled past situations and if you fit well with the company culture.
Post-Interview Offer Conversations: Finally, you’ll talk about salary, benefits, and other job details.

Recruiter Screen

The first chat with the recruiter is really important. They want to see if you’d mesh well with the company’s vibe and team. Be ready to talk about how your values align with the company’s goals, why you’re excited about the job, and what you can bring to the table. Sharing your relevant experiences and showing your enthusiasm can really help.

Technical Phone Screen

In this round, you’ll face coding problems that test not only your tech skills but also how you think through problems. Many companies use a list of common coding questions, so practicing these can help a lot. Remember, it’s not just about getting the right answer but showing that you understand the problem and can think critically about solutions.

Take Home Challenge

This challenge lets you work at your own pace on a more significant project. It’s your chance to shine by going beyond the basics. Put extra effort into writing clean, organized code and thinking through your design choices. This shows you care about quality and have a solid grasp of good coding practices.

On-Site Technical Rounds

When you get to the onsite interviews, you’ll go through several rounds that test different tech skills. This might include writing code, designing systems, and sometimes even discussing how you’d handle specific work scenarios. Practicing different types of tech problems can really help you feel prepared.

On-Site Behavioral Rounds

These interviews look at how you fit as a person within the company. You’ll talk about your past work experiences, how you solve problems, and how you handle teamwork. Being open about your experiences and how they align with the company’s culture is key here.

Post-Interview Offer Conversations

The last step is talking about the job offer. This is when you discuss what the company will pay you, what benefits they offer, and any other details about the job. It’s your chance to negotiate and make sure the offer meets your needs and expectations.

Understanding the interview process from start to finish can make everything less stressful and more manageable. By preparing for each stage, you’ll improve your chances of success and feel more confident about landing the job you want. This guide is here to help you navigate through each step, ensuring you’re ready to tackle any challenge the interview might throw your way.

Recommended Study Plan

This guide lays out a suggested four-month plan for prepping for your frontend interviews, but if you’re crunched for time, don’t worry — we’ve got shorter plans, too, ranging from two weeks to three months, you can find them here.

Week 1: Basic Data Structure and Algorithmic Knowledge Kick off your prep by building a strong base in data structures and algorithms. Focus on:

Stacks and queues
Basic tree traversal
Hashmaps and their applications
Recursion and memoization
Understanding Big O notation for efficiency analysis

Getting these fundamentals down will not only help with the coding tests but also prepare you to tackle more complex problems down the line.

Week 2: Fundamental JavaScript, HTML, and CSS Knowledge Dive into the essentials of frontend development:

Master JavaScript array and object methods
Understand the nuances of JavaScript like strict equality and type conversions
Study important concepts like closures, the “this” context, and object-oriented JavaScript
Explore functional programming and design patterns

Weeks 3 to 4: JavaScript Trivia Questions Prepare to explain key JavaScript concepts clearly, such as closures, the difference between .call() and .apply(), and event delegation. These often come up during interviews.

Weeks 5 to 10: Tackling JavaScript Interview Questions Apply what you’ve learned by solving common interview challenges like creating debounce functions, implementing throttling, and building custom promises.

Weeks 11 to 12: App Design Using Vanilla JavaScript and React Now’s the time to put your skills into practice by designing and building small applications. Create todo apps, image carousels, and more complex UI components to demonstrate your ability to handle real-world projects.

Weeks 13 to 16: Frontend System Design The final phase of your technical prep involves understanding and designing large-scale systems. Focus on:

Requirement gathering
Architectural design
API design considerations (REST vs GraphQL)
Performance optimization
Enhancing user experience with a focus on accessibility and responsiveness

Weeks 16+: Behavioral Interview Prep Don’t overlook the behavioral interview. Practice the STAR answer format to structure your responses effectively, and prepare answers that reflect your experiences and alignment with the company’s values.

Offer Negotiation As you approach the finish line, prepare to negotiate your job offer. This is about knowing your worth and being able to articulate it confidently, which is as crucial as acing the technical parts of the interview.

Prepping for frontend interviews is a serious undertaking, but with a disciplined approach and this detailed study plan, you’re setting yourself up for success. Remember, every expert coder started somewhere — nervous and excited but ready to succeed. Use this guide to navigate your way through the interview process, from basic coding to negotiating your job offer.

HTML Fundamentals

HTML (HyperText Markup Language) is the backbone of web content, defining the structure of web pages using a system of tags and attributes. Tags like <p> for paragraphs and <a> for links are the basic building blocks, creating elements on the page. Attributes, such as src in an <img> tag, provide additional information about these elements. The fundamental tags include <html>, <head>, <body>, <div>, and <span>, each serving specific structural functions.

Lists, links, images, and tables are common HTML elements used to organize and display content effectively. Forms, defined with the <form> tag, collect user input and are essential for interactive sites. HTML's role in front-end development is crucial, as it lays the groundwork for styling (CSS) and functionality (JavaScript), which are often evaluated in frontend interviews.

For a deeper dive into HTML and how it can enhance your frontend interview prep, click our free article here.

CSS Fundamentals

CSS (Cascading Style Sheets) is used to style and layout web pages. It allows you to specify text colors, font styles, and other visual elements through selectors like classes and IDs. Key CSS properties manage layouts (e.g., margins, padding, borders) and enhance aesthetics (e.g., background-color, font-size). The box model is crucial, consisting of margins, borders, padding, and the content area, helping developers control spacing and positioning effectively.

Advanced features like Flexbox and Grid provide powerful options for creating responsive designs, and media queries allow for style adjustments based on device specifics, making CSS indispensable for responsive design. Understanding CSS is vital for frontend interviews, as it demonstrates proficiency in creating visually appealing, efficient user interfaces.

For more detailed insights on CSS and its impact on frontend interview success, check our free article here.

Javascript Fundamentals

JavaScript is the scripting language that brings web pages to life by adding interactivity and complex functionalities. It operates on client-side browsers to enhance user experience and allows developers to manipulate HTML and CSS programmatically. Core JavaScript concepts include variables, functions, and data types, which form the backbone of scripting logic.

Control structures like loops (for, while) and conditionals (if-else) are essential for handling decisions and repeating tasks. JavaScript also supports events and event handling, crucial for responding to user interactions such as clicks and key presses.

Arrays and objects are vital data structures in JavaScript, enabling developers to store, access, and manipulate data efficiently. More advanced topics include closures, promises, and asynchronous programming, which are critical for performing operations that depend on timing or external data, such as fetching data from a server.

For frontend interviews, a strong grasp of JavaScript is necessary, as it tests a candidate’s ability to implement dynamic client-side functionalities. Understanding these JavaScript fundamentals not only aids in interview preparation but also in practical web development tasks.

For an in-depth guide to JavaScript and how it can boost your frontend interview prep, check out our free article here.

Data Structure and Algorithmic Fundamentals

In frontend interviews, a strong understanding of data structures and algorithms is crucial, as it demonstrates your ability to solve problems efficiently and optimize web applications. Key concepts include:

Arrays and Strings: Often used in frontend development for data management and manipulation, arrays and strings are essential for tasks like sorting data or managing user inputs.
Objects and Hash Tables: JavaScript objects, often used as hash tables, are vital for quick data retrieval and storage operations. Understanding how to leverage key-value pairs efficiently can significantly enhance the performance of web applications.
Stacks and Queues: These can be used in UI developments such as undo mechanisms in text editors or handling asynchronous tasks like AJAX requests in a controlled sequence.
Trees and Graphs: While more common in backend development, frontend developers might encounter them in scenarios like DOM manipulations or when implementing features that require hierarchical data structures, such as menu systems.
Algorithms: Sorting algorithms (like quicksort and mergesort) and searching algorithms (like binary search) are important, especially in optimizing performance-critical applications such as those handling large datasets.

Understanding these data structures and algorithms is not only crucial for acing technical interviews but also plays a significant role in writing efficient and scalable frontend code. By mastering these areas, you’ll be better equipped to tackle common frontend challenges, leading to more optimal and effective solutions in your projects.

For more detailed insights on data structures and algorithms tailored for frontend interviews, check out our free article here.

Frontend Trivia Questions

Preparing for frontend interview questions can be a daunting task, but with the right approach and resources, you can confidently showcase your skills and knowledge.

Here are some of the top questions you can expect in frontend interviews:

HTML Concepts

What is the difference between <div> and <span> elements?
Explain the purpose of semantic HTML tags and their importance.
How do you make a web page accessible for users with disabilities?

CSS Fundamentals

What is the box model in CSS, and how does it work?
Explain the difference between inline, block, and inline-block elements.
How do you center an element horizontally and vertically using CSS?

JavaScript Essentials

What is the difference between let, const, and var in JavaScript?
Explain the concept of closures in JavaScript.
How do you implement event delegation in JavaScript?

Front-end Frameworks/Libraries

What are the advantages of using a front-end framework like React or Angular?
How does React’s virtual DOM work, and why is it important?
Explain the concept of state management in front-end frameworks.

Web Performance Optimization

What are some techniques you can use to optimize website performance?
How does browser caching work, and how can you leverage it?
Explain the concept of code splitting and its importance in web applications.

Responsive Web Design

What is the difference between responsive and adaptive web design?
How do you implement media queries in CSS for responsive design?
Explain the concept of mobile-first design and its advantages.

Version Control with Git

What is the difference between git pull and git fetch?
How do you resolve merge conflicts in Git?
Explain the purpose of Git branches and their importance in collaboration.

Build Tools and Task Runners

What is the purpose of using a build tool like Webpack or Rollup?
How do you configure Webpack for a React or Angular project?
Explain the concept of hot module replacement (HMR) and its benefits.

Modern Web Technologies

What is the purpose of Web Components, and how do they work?
Explain the concept of Progressive Web Apps (PWAs) and their advantages.
How do you implement server-side rendering (SSR) in a front-end application?

You can find a in depth list of questions to expect here.

Javascript interview questions

Lets show case the 75 most commonly asked Frontend interview questions in JavaScript.

Remember, understanding the question is just as crucial as knowing the answer. It’s not enough to have a superficial grasp of the solutions; what sets candidates apart is their ability to apply the most efficient and optimized solutions to problems, particularly in the fast-evolving field of front-end development. To aid in this, we introduced frontendlead.com, a resource designed to offer in-depth explanations and video tutorials for each question, ensuring you’re well-equipped to tackle any challenge that comes your way in a front-end engineering interview.

Frontend build an app interview questions

Preparing for app design questions in frontend interviews is essential for demonstrating your ability to handle real-world programming scenarios. These tasks often involve creating a mini-application, such as a to-do list, photo gallery, image slider, masonry layout, or even a simple game. This process evaluates your skill in applying design principles, coding, and planning the architecture of an application. It also tests your ability to make thoughtful choices about user interface (UI) and user experience (UX), as well as your proficiency with specific technologies like React or Vanilla JavaScript.

To excel in these challenges, practice is crucial. Building small projects regularly will familiarize you with typical requirements and effective solutions. Start by outlining the core functionalities of each app, consider component structuring in React, or direct DOM manipulation in Vanilla JavaScript. Pay attention to performance optimization and code readability, as these are key to creating efficient and maintainable code. For practical examples and further practice, visit frontendlead.com. This platform offers a range of app design questions and projects tailored to enhance your coding skills and prepare you for any frontend development interview.

Below is a table showcasing typical app design questions you might encounter, with examples in both React and Vanilla JavaScript:

App Type: To-do List

Description: Create an app to manage daily tasks.
React Example: Use state to manage list items.
Vanilla JS Example: Manipulate DOM to add/remove tasks.

2. App Type: Photo Gallery

Description: Develop a grid-based photo display app.
React Example: Use components for gallery items.
Vanilla JS Example: Use CSS Grid for layout.

3. App Type: Image Slider

Description: Build a carousel for navigating through images.
React Example: Implement with React state for active slide.
Vanilla JS Example: Use timers and DOM manipulation.

4. App Type: Masonry Layout

Description: Create a Pinterest-like column-based layout.
React Example: Use CSS Modules for styling.
Vanilla JS Example: Apply column-width CSS dynamically.

5. App Type: Tic Tac Toe

Description: Design a game with minimal user interface.
React Example: Use React state for storing game board.
Vanilla JS Example: Track clicks and check for win conditions.

6. App Type: Small Game

Description: Develop a simple interactive game like Snake.
React Example: Leverage React effects for game logic.
Vanilla JS Example: Use Canvas API for rendering.

Developing these projects will not only prepare you for potential interview questions but also enrich your portfolio, showcasing your skills to prospective employers. During your preparation, remember to articulate your design decisions and discuss potential enhancements to demonstrate your thought process and technical knowledge.

Frontend system design questions

Understanding Front-End System Design involves a comprehensive evaluation of how components interact within the client-side of a web application and the API design between the client and the server. This section delves into the critical elements and processes that candidates are expected to master for front-end system design interviews.

If you would like a more in depth free guide, we recommend exploring our all in one frontend system design prep guide.

Behavioral questions

Behavioral interviews for software engineers are not just about assessing technical prowess; they delve deeper into a candidate’s soft skills, such as leadership, communication, collaboration, and problem-solving abilities. These interviews employ behavioral interview questions to unearth the candidate’s past behavior in specific scenarios, effectively predicting their future behavior in similar circumstances. This emphasis on past experiences and behaviors acknowledges that soft skills are equally pivotal as technical capabilities in software engineering roles, ensuring a comprehensive evaluation of a candidate’s suitability for a position.

Check out our free in depth guide that can help you prepare for behavioral interview questions.

Salary Negotiation

Negotiating a job offer is a crucial skill for software engineers, reflecting their understanding of their worth and their ability to secure favorable terms. This is especially important in a high-demand field where options are plentiful and each decision impacts career trajectory.

A successful negotiation extends beyond salary discussions; it includes bonuses, roles, responsibilities, and work conditions. Mastering this art involves recognizing your value, thorough research, precise timing, clear communication, and handling objections gracefully.

Understanding Your Value: Start by assessing your technical skills, such as proficiency in critical algorithms and software development, which are key to tech innovations. Document your achievements and certifications to create a compelling value proposition that clearly outlines what you bring to the table.

Market Research: Use resources like Levels.fyi and Payscale to understand standard compensation for your role and experience level. Consider local demand for your skills and how specific companies have compensated similar roles.

Strategize Your Negotiation Approach: Emphasize your potential for growth and leverage any competing offers to strengthen your position. Tailor your strategy based on your level of experience — new grads might focus on growth opportunities, while seasoned professionals can negotiate based on proven impact.

Preparation and Timing: Familiarize yourself with all aspects of the offer and determine your salary expectations and minimum acceptable offer, but keep these private. Practice how you’ll present your case to negotiate confidently.

For a more in-depth guide on negotiating as a software engineer and how this can enhance your interview preparation, check out our free article here.

How to not screw up the negotiation

Navigating job offer negotiations can be tricky, and even seasoned software engineers can make common errors that undermine their potential job terms. Understanding what to avoid can significantly enhance your ability to secure a favorable outcome.

Common Pitfalls in Negotiation:

Lacking Preparation: Entering negotiations without thorough research on the company, industry salary standards, and your own value can leave you vulnerable. It’s essential to come prepared with a clear understanding of what you deserve and the flexibility of the offer components.
Accepting Too Quickly: While it might be tempting to accept an offer right away, especially if it meets your expectations, taking the time to fully consider all aspects of the offer is crucial. This includes benefits, potential for growth, and alignment with your career goals.
Focusing Solely on Salary: Although salary is a significant part of the compensation package, other elements like bonuses, equity, work-life balance, and professional development opportunities can also be highly valuable.
Poor Communication: Being too aggressive or too passive can work against you. It’s important to maintain a professional demeanor, clearly articulate your expectations, and negotiate assertively yet politely.
Not Recognizing When to Walk Away: Understanding your deal-breakers and recognizing when an offer doesn’t meet your minimum requirements is crucial. Holding out for a better opportunity can sometimes be more beneficial than accepting an unsatisfactory offer.

Strategies for Effective Negotiation:

Thorough Preparation: Before entering negotiations, prepare by understanding your market value, the company’s compensation trends, and your minimum acceptable offer. Use tools and resources to gather this information.
Evaluate the Entire Package: Consider all aspects of the offer, not just the salary. Evaluate how other benefits contribute to your overall job satisfaction and long-term career goals.
Communicate Effectively: Practice your negotiation points, focusing on clear and concise communication. Express enthusiasm for the position while also stating your case for a better offer.
Know Your Worth: Be confident in your skills and experience. Demonstrating awareness of your value can influence the negotiation in your favor.

For a deeper understanding of negotiation strategies and to avoid common mistakes, check out our comprehensive guide on job offer negotiation for software engineers here. This guide provides detailed insights to help you navigate this critical aspect of your career development effectively.

Conclusion

Understanding that preparing for these interviews isn’t always the most exciting task, the guide aims to provide a comprehensive toolkit for success. It focuses on real-world questions specific to frontend technologies like HTML, CSS, and JavaScript, differing from the typical software engineering interviews that often focus more on algorithms.

The guidebook thoroughly details the various stages of the frontend interview process, from initial screens and technical assessments to the final offer discussions. It breaks down essential topics such as HTML, CSS, JavaScript fundamentals, and more advanced areas like system design and behavioral questions. This structured content is designed not only to prepare candidates for practical interview questions but also to help them understand the full scope of the role and responsibilities of a frontend developer.

Additionally, the guide emphasizes the importance of community within the frontend development sphere. It encourages sharing and collaboration among developers to stay ahead in a rapidly evolving industry. The guidebook is available for free on frontendlead.com, reflecting a commitment to accessible, high-quality resources for developers at all stages of their career. By equipping candidates with the right knowledge and strategies, the guide aims to boost confidence and proficiency, making the daunting process of job interviews a little more manageable and a lot more successful.

Best of luck on your interviews!