11 Full-Stack Developer Interview Questions


You’ve landed an interview for a new position as a Full-Stack Developer. That’s fantastic, exciting, and maybe even a little nerve-wracking. Don’t worry. It’s normal to be nervous about something you’re really looking forward to.

To make you feel more at ease in the interview, we’ve created this list of common questions to help you prepare. We’ve included potential answers that you can review, as well as a few tips to keep your coding and interviewing skills sharp. 

You can elevate your interview preparation with our new AI-powered Interview Simulator (currently in beta), which is crafted for Front-End, Back-End, and Full-Stack Developer roles. Practice articulating your responses, whether by typing or speaking, and receive actionable insights on your performance.  

Get started today by upgrading to Codecademy Pro and gain access to the Interview Simulator alongside other essential job search tools like the job-readiness checker and portfolio projects.

Learn something new for free

1. What programming language are you most comfortable working with?

Be sure to answer this question honestly, but also show that you’ve done your homework and learned which programming languages they use. First, answer with your preferred language, whether it’s Python, JavaScript, or C++, and explain why.

If it turns out that the company prefers C++, but you prefer Python, let them know that you also took the time to learn C++ because you know how useful it is and how many companies rely on it. Of course, if you don’t know C++, don’t lie. Instead, tell them that it’s not your strongest language, but you’ll dedicate some time to get more familiar with it.

Because this is a Full-Stack Developer interview, it wouldn’t hurt to mention that you know HTML, CSS, and JavaScript, along with any back-end languages like SQL or Python. You want to show that you have the basics required to be great at your new job.

2. How do you select the tools and technology for your projects?

Don’t let this question stump you if this is your first job as a Full-Stack Developer. You can use your experience with courses, personal projects, or open-source projects online. The interviewer wants to know if you can think critically and select the best tools for the job.

When you answer this question, think about a recent project, website, or program you built. How did you select the programming languages, hosting sites, design elements, and user interface? Explain your thought process and reasoning when answering this question. It’s more about how you came to select the tools/tech than the exact choices you made.

3. How would you make a website as efficient as possible?

There are more than a few ways you can answer this question. Your interviewer may even give you a variation of this question and ask for three ways you can make a website more efficient.

Think about the heavy-hitters — give the most powerful and logical answers first. Explain how you would optimize assets, minimize the code on the page (or reduce duplicate code), or use browser caching.

You can also relate this question to your own experience by explaining how you improved or optimized a website you created. Or maybe you helped a friend who was having issues with their website, and your solution increased efficiency. That’s a great tidbit to add to this answer.

4. Have you worked with any front-end frameworks like React, Angular, or Vue.js? If so, can you discuss your experience with them? 

This ties into the previous question, because frameworks can significantly impact the scalability and performance of web applications. Interviewers may want to know how much experience you have with different frameworks, and how you’ve used them to collaborate and solve problems with other teams. Share your experience with any framework you’ve worked with, and discuss the projects where you applied it, the features you find useful, and any challenges you encountered. 

5. Can you explain the difference between relational and non-relational (NoSQL) databases? When would you choose one over the other? 

Psst, read this blog about the differences between SQL and NoSQL databases and when to use them. This is a pretty common interview question, and you should be prepared to provide a simple comparison between relational and non-relational databases, mentioning key characteristics like data structure and querying methods. Throw in an example scenario where you might choose one over the other. For bonus points, consider taking our Learn MongoDB course to get a grasp on basic NoSQL operations.   

6. Can you define DevOps?

The company you’re interviewing with might be heavily invested in DevOps, so you’ll want to show you can hit the ground running. Explain that DevOps is a method or practice that allows teams to collaborate, communicate, and release software faster and more effectively. Read this blog to learn more about DevOps practices and functions.   

For example, development and IT departments work in cross-functional teams, combining their strengths to create software. DevOps is a way to iteratively develop software in steps, correcting failures as you go and reaching the end product faster than traditional design methods.

7. What is multi-threading?

Multi-threading is when a CPU can execute multiple threads within a program concurrently, using the same processing capacity. You might also want to explain what a thread is to show you aren’t just regurgitating jargon.

A thread is a set of instructions that can be executed at the same time as other threads that are part of the same root process. This approach helps improve speed, for example, when implementing a machine learning algorithm.

8. Describe your experience with continuous integration and continuous deployment (CI/CD) pipelines. How have you used them in your projects? 

Full-Stack Developers are involved in both front-end and back-end development, and they often use CI/CD pipelines to automate tasks and streamline workflows. This set of tools and practices helps you catch bugs earlier and contribute to efficient project delivery. Check out our free course Intro to DevOps to learn more about the practices and tools that development teams use.

9. What version control systems are you familiar with, and which do you prefer? Why? 

Developers use version control systems (aka VCS) to manage code changes, track revisions, and collaborate effectively. They maintain a complete history of the codebase, so that multiple devs can make changes (without overwriting). The interviewer wants to know how well you can manage code, collaborate with teams, and follow software development best practices.

Mention any version control system you’ve used and briefly explain your workflow, like creating branches, committing changes, and resolving conflicts. Got a strong feelings about why one VCS is better than another? Talk about your experience and preferences. If you want to refresh your knowledge of one of the most popular VCS, check out our free course Learn Git & GitHub.

10. Can you explain what an application server is?

As a Full-Stack Developer, this is a concept you want to be familiar with. An application server allows you to design and maintain applications on both the server- and the client-side. In essence, it hosts the web applications that the end-user interacts with and the environments required to run them.

11. How do you stay updated with the latest trends and technologies in full-stack development? 

The tech landscape is constantly evolving, with new frameworks, languages, tools, and best practices emerging all the time. If you actively follow industry trends, you’ll be aware of new opportunities, advancements, and shifts in technology that could impact your work.

You don’t have to constantly refresh Hacker News to stay up to date. Mention a few reliable sources you use to stay informed about new technologies and trends, like tech blogs (including this one!), influencers, newsletters, and coding communities. It also helps to talk about how you make time to learn new technologies and upskill into your daily life.

More tips to prepare for your Full-Stack Developer interview

Now that you’ve reviewed possible questions for your Full-Stack Developer interview, practice providing your own answers with our AI-powered Interview Simulator (currently in beta). You can customize the interview scenario for a specific role in full-stack, front-end, or back-end development.   

You can also sign up for one of our online skill paths that help you pass the technical interview with JavaScript, Python, or Java. Before you start, be sure to research the company’s preferred programming languages and read the job description closely. 

Don’t forget that practicing your programming skills is one of the best ways to prepare for your interview. Solving problems with code will keep programming concepts fresh in your mind. A bonus? You might even solve a problem or experience a challenge that you can discuss in your interview. 

Lastly, don’t worry if you don’t know the answer to one of your interviewer’s answers. Take a deep breath and explain that you aren’t sure off the top of your head, but you can explain exactly how you’d determine the answer through research and communication. 

To prepare for your career as a Full-Stack Developer, learning the required skills, building a portfolio, and preparing for technical interviews, check out our Full-Stack Engineer Career Path

This blog was originally published in September 2021 and has been updated to include more questions and details about new job-readiness features.  

Related courses

4 courses

Related articles

7 articles