Full Stack Developer Interview Questions

The demand for Full Stack Developers is growing. If you wish to make your career as a full stack developer at FAANG, you should know commonly asked Full Stack Developer interview questions.

To be able to outperform the competition, your interview prep has to be extensive. And that’s why we have compiled a list of frequently asked full stack interview questions and answers that will help you to boost your tech interview prep.

Having trained over 17,000 software engineers and developers, we know what it takes to crack the toughest tech interview questions at FAANG and other tier-1 tech companies.

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In this article, our focus will be on covering the most common full stack interview questions asked at FAANG and other top tech companies.

Here’s what we’ll cover:

• Skills Required to Crack Full Stack Development Interview Questions
• Top Full Stack Web Developer Interview Questions and Answers
• Sample Full Stack Developer Interview Questions
• Sample Full Stack Developer Interview Questions on Java
• FAQs About Full Stack Developer Interview Questions

What Are the Skills Required to Crack Full Stack Development Interview Questions?

Before we get into full stack developer interview questions, let’s quickly go over what full stack development means. Full stack development includes simultaneously developing the front end and back end of web applications. This process involves three layers:

• Presentation layer (front end — user interface)
• Business logic layer (back end — the server-side of the application)
• Database layer

Full stack developers or engineers can code on both the front end (user interfaces) and the back end (running programs). As a full stack developer, you are expected to know the “full stack” of technology, i.e., they can develop software for both the user and service provider. You should also be skilled in Java, JavaScript, HTML, C++, etc., to develop applications and know how to program browsers, servers, and databases.

The following skills are essential to ace full-stack developer interview questions:

• Competency in HTML, CSS, SQL, etc.
• Front-end Frameworks: BootStrap, AngularJS, VueJS, ReactJS, Ruby, JavaScript, TypeScript, Python, and PHP.
• Back-end Frameworks: Express, NodeJS, Django, Ruby on Rails
• Databases: MySQL, SQLite, Postgres, MongoDB, Sphinx, Cassandra, Apache Storm.
• Auxiliary Skills: Git, Machine Learning, SSH, Data Structures, Linux Command, Character encoding.

Top Full Stack Developer Interview Questions and Answers

To help you prepare for your upcoming tech interview, here are the most commonly asked Full Stack Developer Interview Questions.

1. What are the latest trends in Full Stack Web Development?

Full stack developer interview questions include talking about the latest trends in the field. If you are applying for full-stack development, you should know the following:

• Rise of Vue JS Functional, real-time web apps, mobile web development, and progressive apps.
• Programming with improvement in JavaScript.
• Evolution of more compatible extensions.

2. What are some Stack Developer tools that you’ve worked with?

Stack developer tools form an integral part of full stack developer interview questions. Some popular and efficient stack developer tools are:

• WebStorm
• Visual Studio Code
• Backbone
• Slack
• Electron
• TypeScript
• GitHub
• CodePen

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Elaborate on your experience and expertise in any of these tools based on your experience.

3. Explain DevOps.

DevOps is a technique that emphasizes the coordination and communication of both software developers and other IT professionals. DevOps aims to deliver software products faster and decrease release failure rates.

You can also expect questions specific to Azure DevOps, Jenkins, and other DevOps tools during your Full Stack Developer Interview.  

4. Explain Pair Programming.

When it comes to full stack developer interviews, pair programming is a critical topic, and you can expect many questions related to it.

Pair Programming is among the core elements of extreme programming, which involves two developers working on the same terminal. One of the developers who is responsible for writing the codes is called the driver, and the other whose task is to review the codes is the navigator. Pair programming works for both frontend and backend.

5. What do you mean by data attributes?

To be able to crack full stack interviews, you have to be well-versed with HTML and its features. This is one example of a question related to HTML 5 that you can expect.

HTML 5 has data attributes that the developer defines. These are custom attributes used when the existing properties are not suitable for usage. You can use data attributes only on the page they are written on, and they do not require AJAX calls. These are global attributes that you can apply to any element.

6. Explain multithreading and continuous integration.

Questions on multithreading are quite common at full stack developer interviews.

Multithreading is the process of improving the performance of the CPU. It is typically the ability of a program, where multiple users can manage it simultaneously. Multithreading is when the operating system duly supports the execution of multiple processes.

Continuous integration is the execution of specially designed codes that are automated for testing. It simply helps the developers to implement the codes during the production time. Continuous integration aids in detecting errors faster and resolving them easily. That is why web developers prefer to integrate codes several times a day.

7. Explain Long Polling.

Long Polling is a pattern in web development that the developers use to boost pushing up data from the server toward the client.

Through Long Polling, the client requests information from the server. When the server doesn't have any information about the client, it holds the request and waits until some information is available rather than sending an empty resource.

During your full stack developer interview, you can also expect questions like "what's the difference between Long Polling with WebSockets?"

8. What is CORS?

CORS stands for Cross-Origin Resource Sharing. We use this process to gain the authority of various web resources over different domains. With CORS, the Integration of web scripts is executed more effortlessly with the external content of the indigenous domain.

9. How can we enhance the scalability and efficiency of a website?

This is one crucial full stack developer interview question. The best ways to enhance scalability and efficiency are:

• Reducing DNS lookup
• Avoiding duplicate codes
• Avoiding URL redirects
• Leveraging browser caching
• Avoiding unnecessary images
• Avoiding inline JavaScript and CSS
• Deferring parsing of JavaScript
• Placing all assets on a cookie-free domain, preferably using a CDN.
• Using srcset attribute for responsive images

10. What are the types of design patterns?

A design pattern is a reproducible or reusable solution for frequent problems in software design. Such patterns show the relationships and interactions between classes and objects. There are three main types of design patterns:

• Creational: Related to class instantiation and object creation. These are further categorized into class-creational patterns and object-creational patterns.
• Structural: Related to the organization of different classes and objects to provide new and more extensive functionality.
• Behavioral: Concerned with identifying common communication patterns between objects.

11. What is an Application server, and what is a RESTful API?

Questions related to SOAP and RESTful API are favorites at full-stack developer interviews. An application server is a software framework that enables the creation of both web applications and server environments. It comprises an exhaustive service layer model and supports different protocols and APIs (application programming interfaces).

REST stands for representational state transfer. A RESTful API (or REST API) is an architectural style for an API or web API that uses HTTP requests to procure and manage information. Such data can be used to POST, GET, DELETE, and OUT data types, referring to reading, creating, deleting, and operations services.

12. What is Event Bubbling and Capturing in JavaScript?

You must pay special attention to HTML and JavaScript while preparing for full stack developer interview questions.

In HTML API, Event Bubbling and Event Capturing are the ways of the event propagation when an event takes place in an element located inside the other part.

Both the parts have registered a handle with the recent Event. The event propagation mode determines the order in which the elements receive the Event. In Event Bubbling, the Event is primarily captured and handled by the innermost part, and then it is propagated to the outermost part.

13. Explain the concept of a Docker?

Docker is an effortless method to execute virtual machines on your local machine or in the cloud. Although they are not strictly separate machines and do not need an operating system to boot, they offer many benefits.

For example, we can use them to create test blocks to support the ongoing integration testing during deployment. Also, it can encapsulate legacy applications to facilitate them to be deployed to servers that wouldn't be easy to configure otherwise.

4. Distinguish between Server-side Scripting and Client-side Scripting.

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15. What is a Connection Leak in Java, and how can we fix it?

Java is a critical topic when it comes to full-stack development. This is one example of a full-stack developer interview question on Java.

A Connection Leak in Java is a condition when the developer forgets to close the JDBC connection. The most common type of Connection Leak in Java web development is when using a Connection Pool, like DBCP. We can fix a connection leak by closing the connection and paying special attention to the error handling code.

16. How can you enhance your website load time and performance?

This full stack developer interview question is vital for your tech interview prep. Different possible ways to optimize your website for the best performance are:

• Minimize HTTP requests.
• Browser caching.
• Utilize CDNs and remove unused files/scripts.
• Apply CSS3 and HTML5.
• Optimize files and compress images.
• Optimize caches.
• Minify JavaScript and Style Sheets.

17. Explain the difference between Normalization and Denormalization.

The differences between Normalization and Denormalization are:

18. What is Callback hell, and how to fix it?

Many full stack developer interview questions are about explaining certain technical terms. A phenomenon in JavaScript in which the developer tries to implement multiple asynchronous operations together is called Callback hell.

The nesting of callback functions to easily finish up with hard-to-read, error-prone, and hard-to-manage code.

We can efficiently resolve it by using these methods:

• Split large functions into smaller functions
• Use Promises
• Use Async or Wait

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Sample Full Stack Developer Interview Questions

Following are some more full stack developer interview questions that you can practice for your next tech interview prep:

1. State the success factors for successive integration?
2. What is your favorite coding language, and why?
3. What is the most important quality in a full stack developer?
4. How to prevent a bot from scraping a publicly accessible API?
5. State the differences between REST and GraphQL.
6. Explain referential transparency in functional programming.
7. How to find a memory leak?
8. Explain the architectural designs primarily used to design applications.
9. How can you share code between files?
10. Explain the Gitflow workflow.

Sample Full Stack Developer Interview Questions on Java

If you are experienced in Java, you can expect a few questions on Java during your Full Stack Developer Interview: Here are a few examples of full stack developer interview questions on Java:

1. What is double brace initialization in Java, and where is it used?
2. How to avoid deadlock in Java?
3. What is a critical section?
4. What is the SOLID principle in Java?
5. Why is map not part of the collection interface in Java?
6. What is the difference between composition and inheritance? Which would you use and why?

We hope these full stack developer interview questions will help you elevate your tech interview prep and excel in your upcoming Full Stack Developer interview. For more guidance, check out our Full Stack Developer Interview Preparation Blog.

FAQs Abut Full Stack Developer Interview Questions

Q1. Why are Full Stack Developers in demand?

Full stack developers are in high demand across the tech industry due to their vast knowledge and versatility. Full stack developer interview questions are designed to choose the most skilled candidates who can work in various divisions.

Their deep understanding of technical concepts enables them to cope with challenging environments. They prove valuable assets for both budding startups and thriving organizations.

Q2. What skills are required to crack full stack developer interview questions?

Full stack developer interview questions are aimed at analyzing your frontend and backend coding abilities. Interviewers seek whether you are adept in designing user interfaces on websites, developing servers and databases for website functionality, and implementing codes for mobile platforms or not.

Q3. Is a Java developer a full stack developer?

They can be. Full stack development includes simultaneously developing the frontend and backend of web applications. A web developer who uses Java to develop the entire technology stack is called a Java full stack developer.

Q4. What skills do I need to crack full stack developer interview questions?

Competency in HTML, CSS, SQL, etc.; expertise in Front-end Frameworks like BootStrap and AngularJS; experience in Backend Frameworks like NodeJS and Django; proficiency in databases (MySQL, SQLite, etc.); knowledge of Git, Machine Learning, SSH, Data Structures, Linux Command, Character encoding.

Q5. What is the salary of a full stack developer?

A full stack developer in the US earns an average of $106,167 per year, with a $4,750 annual bonus (Indeed.com).

Ready to Nail Full Stack Developer Tech Interview Questions?

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