Top 50+ Full Stack Developer Interview Questions and Answers

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A full stack developer works on both the front-end (what users see) and the back-end (how things function behind the scenes) of a web application. This role requires knowledge of multiple programming languages, databases, and frameworks to build a fully functional system. Since full stack developers work with a wide range of technologies, interview questions can cover many topics. To help you prepare, we have researched the most commonly asked full stack developer interview questions and compiled them into this guide. We have also provided simple answers to help you understand key concepts quickly

Fun Fact: Over the past year, full-stack developer jobs in India have grown by more than 30%.

Note: We have categorized these full stack developer interview questions into basic, fresher-level, experienced, advanced, and company-specific sections for easy understanding. 

Basic Full Stack Developer Interview Questions

Here is a list of basic full stack developer interview questions and answers: 

1. What is full stack development?

Full stack development refers to the ability to work on both the front-end and back-end of a web application. The front-end deals with what users see and interact with. The back-end handles data processing, databases, and server-side logic. A full stack developer must be proficient in both areas to build complete web applications.

2. Explain the difference between client-side and server-side programming.

Client-side programming runs in the user’s browser and focuses on user interface and experience. It includes HTML, CSS, JavaScript, and frameworks like React or Angular. 

Server-side programming runs on a server, handling data processing, authentication, and business logic. It involves languages like Python, Node.js, Java, or PHP, along with databases and APIs.

3. What are the key responsibilities of a full stack developer?

A full stack developer is responsible for –

• Designing and developing front-end and back-end components.
• Writing clean, efficient, and scalable code.
• Integrating databases and managing data storage.
• Creating and consuming APIs.
• Troubleshooting and debugging issues.
• Collaborating with designers, developers, and stakeholders.
• Optimizing applications for performance and security.

4. Describe the purpose of HTML, CSS, and JavaScript in web development.

• HTML (HyperText Markup Language): Defines the structure of a webpage, including elements like headings, paragraphs, and images.
• CSS (Cascading Style Sheets): Controls the styling and layout of web pages, including colours, fonts, and positioning.
• JavaScript: Adds interactivity to web pages, allowing for dynamic content, animations, and real-time user interactions.

Also Read - Top 40+ HTML CSS JavaScript Interview Questions and Answers

5. What is a RESTful API, and why is it used?

A RESTful API (Representational State Transfer) is a way for applications to communicate over HTTP. It follows principles like statelessness, resource-based URL structure, and standard HTTP methods (GET, POST, PUT, DELETE). REST APIs are used to connect front-end applications with back-end services, enabling seamless data exchange between client and server.

Also Read - Top 50+ REST API Interview Questions and Answers

Full Stack Developer Interview Questions for Freshers

Here are some commonly asked full stack interview questions and answers for freshers:

6. What is multithreading, and how is it used?

Multithreading allows a program to run multiple tasks simultaneously by creating multiple threads. This improves performance by enabling concurrent execution of code. In web development, multithreading is used in servers to handle multiple user requests at the same time, ensuring smooth application performance.

7. Can you explain the concept of pair programming?

Pair programming is a software development practice where two developers work together on the same code. One developer (the “driver”) writes the code, while the other (the “observer” or “navigator”) reviews it in real time. This approach helps catch errors early, improves code quality, and promotes knowledge sharing among developers.

8. What is CORS (Cross-Origin Resource Sharing)?

CORS is a security feature that restricts web pages from making requests to a different domain than the one they were loaded from. Browsers enforce CORS to prevent malicious cross-site requests. Developers can allow cross-origin requests by configuring server-side headers such as Access-Control-Allow-Origin.

9. Describe the MVC (Model-View-Controller) architecture.

MVC is a design pattern used for organizing code in web applications.

• Model: Handles data and business logic.
• View: Manages the user interface and presentation.
• Controller: Acts as a bridge between the model and view, handling user input and updating data accordingly.

This structure helps separate concerns, making applications more maintainable and scalable.

10. How do you keep a web application secure?

Securing a web application involves –

• Validating user input to prevent SQL injection and XSS attacks.
• Using HTTPS to encrypt data transmission.
• Implementing authentication and authorization mechanisms.
• Storing sensitive data securely using hashing and encryption.
• Keeping dependencies and libraries updated to fix security vulnerabilities.

Note: These are some interview questions full stack developer candidates are frequently asked.

Also Read - Top 20+ Java Multithreading Interview Questions

Full Stack Web Developer Interview Questions for Experienced 

Let’s go through some important full stack developer interview questions and answers for experienced candidates: 

11. How do you optimize SQL queries for better performance?

To optimize SQL queries:

• Use indexes on frequently queried columns.
• Avoid SELECT* and fetch only necessary fields.
• Use JOINs efficiently to reduce redundant data retrieval.
• Use prepared statements for repeated queries.
• Optimize database schema and normalize data where necessary.
• Use caching mechanisms to reduce database load.

12. What strategies do you use to handle browser compatibility issues?

To handle browser compatibility:

• Use standard HTML, CSS, and JavaScript features supported across all major browsers.
• Use feature detection with libraries like Modernizr instead of browser detection.
• Test across different browsers using tools like BrowserStack or built-in developer tools.
• Use CSS prefixes where needed (e.g., -webkit-, -moz-).
• Avoid outdated or deprecated technologies that may not be supported.

Also Read - Top 40+ CSS Interview Questions and Answers

13. Explain the concept of dependency injection.

Dependency Injection (DI) is a design pattern used to manage dependencies between components. Instead of a class creating its own dependencies, they are provided externally. This improves modularity, makes testing easier, and reduces tight coupling in code. DI is commonly used in frameworks like Spring (Java) and Angular (TypeScript).

14. How do you manage state in a React application?

State management in React can be handled using:

• React’s built-in state (useState, useReducer) for local component state.
• Context API for sharing state across components.
• Redux for managing global application state.
• Recoil or Zustand as alternative state management solutions.
• Server-side state management using React Query or SWR for fetching and caching data efficiently.

15. Describe your experience with both front-end and back-end development.

This is one of the most common full stack developer interview questions for 3 years experienced professionals. 

As a full stack developer, I have worked on both front-end and back-end development.

“On the front-end, I have built responsive UIs using HTML, CSS, and JavaScript frameworks like React and Angular. I have experience managing state, improving performance, and handling user interactions.

On the back-end, I have developed RESTful APIs using Node.js and Express, handling authentication, databases (PostgreSQL, MySQL, MongoDB), and business logic. I have also worked with cloud deployment and CI/CD pipelines for scalable applications.”

Also Read - Top 25+ React JS Interview Questions and Answers

Advanced Interview Questions for a Full Stack Developer

These are some advanced full stack interview questions and answers: 

16. What is the difference between GraphQL and REST?

GraphQL and REST are API design approaches. REST uses predefined endpoints (GET, POST, PUT, DELETE) and returns fixed data structures. GraphQL allows clients to request specific data fields, reducing over-fetching and under-fetching of data. Unlike REST, GraphQL operates on a single endpoint, making queries more efficient and flexible for complex applications.

17. Can you explain the concept of microservices architecture?

Microservices architecture breaks applications into smaller, independent services that communicate via APIs. Each service handles a specific function and can be developed, deployed, and scaled independently. This improves fault isolation, scalability, and development speed compared to monolithic architectures. Popular tools for microservices include Docker, Kubernetes, and API gateways.

Note: These are some advanced-level interview questions full stack developer aspirants should know.

Also Read - Top 25 Spring Boot Microservices Interview Questions with Answers

Full Stack Developer Technical Interview Questions

You might also come across technical full stack development interview questions like these: 

18. What is the purpose of a database index?

A database index improves query performance by allowing the database engine to locate data quickly. Instead of scanning the entire table, the index provides a structured way to retrieve rows efficiently. However, excessive indexing can slow down write operations due to the overhead of maintaining multiple indexes.

19. What are web sockets, and how do they work?

WebSockets enable real-time, bidirectional communication between a client and a server. Unlike HTTP, which follows a request-response model, WebSockets keep a persistent connection open, allowing instant data exchange. This is useful for chat applications, live notifications, and online multiplayer games.

Note: Technical interview questions for a full stack developer often include topics on front-end and back-end technologies, databases, and APIs. 

Full Stack Web Development Interview Questions

Here are some frequently asked interview questions for full stack web developer: 

20. How do you make a website responsive across different devices?

A website is made responsive using CSS media queries, flexible grids, and relative units like percentages or em. Front-end frameworks like Bootstrap provide prebuilt responsive components. Testing across devices and using browser developer tools help confirm correct layouts.

21. What is the role of middleware in web development?

Middleware is software that processes requests between the client and server. It handles authentication, logging, request validation, and error handling. In Express.js, middleware functions are executed sequentially, allowing developers to modify requests before reaching the final endpoint.

Technology-Specific Interview Questions for a Full Stack Developer

NET Full Stack Developer Interview Questions

These are some common Dotnet full stack developer interview questions and answers: 

22. What is ASP.NET, and how does it differ from ASP.NET Core?

ASP.NET is a web development framework by Microsoft used for building dynamic web applications. It runs on the .NET Framework and supports Web Forms, MVC, and Web API. ASP.NET Core, on the other hand, is a cross-platform, open-source framework designed for high performance and scalability. It offers built-in dependency injection, better modularity, and improved performance compared to ASP.NET.

23. How do you manage session state in ASP.NET applications?

Session state in ASP.NET is managed using Session Storage, which stores user data temporarily. It can be configured in multiple ways:

• In-Memory Session Storage: Stores data in the application’s memory (default).
• Distributed Session Storage: Stores session data in external storage like Redis, useful for scalable applications.
• Cookie-Based Session Storage: Stores session identifiers in browser cookies.

Session data is accessed using HttpContext.Session and should be properly managed to prevent excessive memory usage.

Also Read - Top 75+ Python Interview Questions and Answers

Python Full Stack Developer Interview Questions

Here is a list of common Python full stack interview questions and answers:

24. What are Python decorators, and how are they used?

Decorators are functions that modify the behaviour of other functions or methods without changing their structure. They are applied using the @decorator_name syntax. For example, @login_required is a common decorator used in Django to restrict access to authenticated users.

25. Explain the Django MVT (Model-View-Template) architecture.

Django follows the MVT architecture:

• Model: Handles database operations and defines data structure.
• View: Processes user requests, interacts with the model, and returns responses.
• Template: Handles the presentation layer, defining how data is displayed to users.

This structure keeps logic separate and makes applications easier to maintain.

Also Read - Top 40 Django Interview Questions Answers (2025)

26. How do you perform form validation in Flask?

This is one of the most important Python full stack developer interview questions for freshers. 

Flask uses WTForms or Flask-WTF for form validation. The form class defines fields and validation rules, and errors are handled before submission. 

Example:

from flask_wtf import FlaskForm

from wtforms import StringField, EmailField, validators

class UserForm(FlaskForm):

    name = StringField(‘Name’, [validators.InputRequired()])

    email = EmailField(‘Email’, [validators.Email()])

This helps prevent invalid data from being processed.

Also Read - Top 30+ Flask Interview Questions and Answers

PHP Full Stack Developer Interview Questions

These are commonly asked PHP full stack interview questions and answers: 

27. What is the difference between include and require in PHP?

Both are used to include external PHP files, but require stops script execution if the file is missing, while include allows the script to continue running even if the file is not found. 

Example:

include ‘header.php’;  // Generates a warning if missing  

require ‘config.php’;  // Generates a fatal error if missing  

28. How do you handle errors in PHP?

Errors in PHP can be handled using:

• error_reporting(E_ALL): Displays all errors.
• set_error_handler(): Defines a custom error handler.
• try-catch blocks: Used for exception handling. Example:

try {

    $db = new PDO(‘mysql:host=localhost;dbname=test’, ‘user’, ‘pass’);

} catch (PDOException $e) {

    echo “Connection failed: ” . $e->getMessage();

}

MERN Full Stack Developer Interview Questions

Here are some important MERN stack developer interview questions for freshers and experienced candidates: 

29. What is the MERN stack, and what are its components?

MERN stands for:

• MongoDB: NoSQL database for data storage.
• Express.js: Lightweight Node.js framework for building APIs.
• React.js: Front-end JavaScript library for UI development.
• Node.js: JavaScript runtime for executing server-side code.

These technologies work together to build full stack web applications.

30. How does MongoDB differ from traditional SQL databases?

MongoDB is a NoSQL database that stores data in flexible JSON-like documents, whereas SQL databases store data in structured tables. MongoDB offers better scalability, schema flexibility, and faster read/write operations for large datasets, but lacks SQL’s strict consistency model.

Laravel Full Stack Developer Interview Questions

Let’s cover some commonly asked Laravel full stack interview questions and answers: 

31. What is Laravel, and what are its key features?

Laravel is a PHP framework used for building web applications. Key features include:

• Eloquent ORM: Simplifies database interactions.
• Blade Template Engine: Provides a clean syntax for views.
• Middleware: Controls request handling.
• Routing System: Manages web routes efficiently.
• Authentication and Authorization: Built-in user authentication features.

32. How do you define routes in Laravel?

Routes in Laravel are defined in the routes/web.php file. 

Example:

Route::get(‘/home’, function () {

    return view(‘home’);

});

Routes can handle different HTTP methods like GET, POST, PUT, and DELETE.

Company-Specific Full Stack Development Interview Questions

IBM Full Stack Developer Interview Questions

1. How do you approach designing scalable web applications?​
2. Describe a challenging problem you solved in full stack development.​
3. How do you stay updated with emerging technologies in the industry?

TCS Full Stack Developer Interview Questions

1. What do you know about full stack web development?
2. Which tools are used for full stack web development?
3. What is virtual DOM?
4. How do you handle tight deadlines in project development?​

Zoho Full Stack Developer Interview Questions

1. What projects have you worked on?
2. How do you ensure code quality and maintainability?​
3. Describe your experience with RESTful API development.​
4. How do you handle user authentication in web applications?

Google Full Stack Developer Interview Questions

1. How would you optimize a slow-performing web page?
2. How do you optimize web applications for performance?​
3. Describe your experience with cloud services and deployment.​
4. How do you approach mobile-first design in web development?

HCL Full Stack Developer Interview Questions

1. Can you explain your understanding of Java concepts, Angular, HTML, and CSS?
2. What is your experience with DevOps practices?​
3. How do you handle version control in collaborative projects?​
4. Describe a time when you had to debug a complex issue in production.

JP Morgan Full Stack Developer Interview Questions

1. How can you optimize the loading of website assets?
2. How do you guarantee the security of financial data in web applications?​
3. Describe your experience with microservices architecture.​
4. What are the new tags for media elements introduced in HTML5?

Microsoft Full Stack Developer Interview Questions

1. Can you describe a recent failure that has taught you something?
2. What is your experience with Azure services?
3. How do you handle API rate limiting in a large-scale application?
4. Explain the difference between monolithic and microservices architecture.

Oracle Full Stack Developer Interview Questions

1. What specific skills or knowledge did you gain from your previous roles that are relevant to this job?
2. What are the key advantages of using Oracle databases in full stack development?
3. How do you optimize SQL queries in large-scale applications?
4. Can you explain the concept of multithreading?

PayPal Full Stack Developer Interview Questions

1. How do you handle payment gateway integration securely?
2. What is the namespace in Python?
3. What are the key security measures needed for handling financial transactions online?
4. Explain how PayPal APIs work in web applications.

Wipro Full Stack Developer Interview Questions

1. How do you approach debugging and troubleshooting a production issue?
2. Which java version have you used?
3. What technologies have you used for API development?
4. Explain the importance of CI/CD in full stack development.

Apple Full Stack Developer Interview Questions

1. How do you optimize a web application for performance on Apple devices?
2. Can you explain your experience with backend development and coding in Java?
3. What is your experience with Swift for full stack development?
4. Explain the concept of memory management in iOS development.

Axis Bank Full Stack Developer Interview Questions

1. How do you secure sensitive banking data in a web application?
2. How familiar are you with database concepts?
3. Explain how you would implement multi-factor authentication.
4. What technologies have you used for transaction processing systems?

Cisco Full Stack Developer Interview

1. How do you handle real-time data in a full stack application?
2. Do you have experience with Spring Boot?
3. What networking protocols have you worked with in web development?
4. Explain how you would develop a secure API for enterprise applications.

Cognizant Full Stack Developer Interview Questions

1. What are the key challenges in maintaining legacy applications?
2. Briefly explain the method you will use to execute an array linked list.
3. How do you integrate third-party APIs into your application?
4. What are streams in C++? What are predefined streams in C++?

Deutsche Bank Full Stack Developer Interview Questions

1. How do you handle high-traffic load in banking applications?
2. Can you write a program related to Java arrays?
3. Explain how data encryption works in web applications.
4. What is your experience with cloud-based database management?

Infosys Full Stack Developer Interview

1. How do you optimize web applications for low-latency performance?
2. Do you have knowledge of basic algorithms?
3. Explain the differences between SQL and NoSQL databases.
4. What security practices do you follow when handling user authentication?

McKinsey Full Stack Developer Interview Questions

1. How do you approach problem-solving in a full stack development role?
2. What are the benefits and disadvantages of using NodeJS?
3. What strategies do you use to optimize database queries?
4. How do you build scalable applications that can handle growing data loads?

Mindtree Full Stack Developer Interview Questions

1. What frameworks have you used for front-end development?
2. What is idempotent in REST API?
3. How do you handle version control in large development teams?
4. Explain how caching improves web application performance.

Nagarro Full Stack Developer Interview Questions

1. What are the benefits of using GraphQL over REST APIs?
2. How do you manage state in large-scale applications?
3. Explain your experience with continuous integration and deployment.

Tech Mahindra Full Stack Developer Interview Questions

1. How do you implement microservices in a full stack application?
2. What are the SOLID principles in software development?
3. What tools have you used for API monitoring and logging?
4. Explain how to optimize JavaScript for better performance.

Verizon Full Stack Developer Interview Questions

1. How do you handle security vulnerabilities in web applications?
2. What techniques do you use for optimizing front-end load times?
3. Explain the role of WebSockets in real-time communication.

Virtusa Full Stack Developer Interview Questions

1. How do you manage multiple database connections in a full stack project?
2. Explain how you use Docker in full stack development.
3. How do you handle state management in a React or Angular application?

Also Read - Top 55+ Docker Interview Questions and Answers

VMware Full Stack Developer Interview Questions

1. What is your experience with cloud-native full stack development?
2. How do you handle distributed computing in web applications?
3. Explain the differences between Kubernetes and Docker Swarm.

Also Read - Top 50+ Kubernetes Interview Questions and Answers

Wrapping Up

So, these are the top 50+ full stack developer interview questions and answers to help you prepare for your next job interview. Covering basic, advanced, and technology-specific topics, this guide guarantees that you understand key concepts.

Looking for full stack developer jobs in India? Hirist is an online job portal designed for tech professionals. Find top job opportunities easily!

FAQs

How do I prepare for a full stack developer interview?

Learn coding, practice common interview questions, and build projects. Also, understand databases, APIs, and problem-solving techniques.

Is 3 months enough for a full stack developer?

If you study daily and practice coding, three months can be enough to learn basics. But mastering it takes more time.

What skills are needed to be a full stack developer?

You need front-end skills (HTML, CSS, JavaScript) and back-end skills (Node.js, Python, databases). Problem-solving and debugging skills are also important.

What is the technical test for a full stack developer?

It usually includes coding problems, debugging tasks, API development, and database queries. Some companies also test system design skills.

How do I clear my full-stack developer interview?

Practice coding daily. Learn databases, APIs, and frameworks. Build small projects. Solve past interview questions and explain your answers clearly.

Is DSA asked in a full-stack developer interview?

Yes, some companies ask Data Structures and Algorithms (DSA) questions. But startups and small firms focus more on real-world coding skills.

What is a full-stack developer’s salary?

According to data from AmbitionBox, full stack developer salaries range from ₹1.8 LPA to ₹15.6 LPA. It depends on experience, skills, and the company.

How many rounds are in a full stack developer interview?

Most companies have 2-4 rounds, including coding, technical discussions, system design, and HR interviews.

Are full stack developer interviews tough?

It depends on the company. Some focus on coding, while others test problem-solving and project experience. Preparation makes it easier.

Will these questions appear in my full stack developer interview?

It depends on the company and role. Many of these questions are commonly asked, but interviews may also include coding tasks and real-world problem-solving.