Home
Discover Me
Projects
Services
Dev Journal
Roadmap & Interview Preps
Contact
Toggle theme
Toggle theme
Full-stack Interview Questions
English
Back to All Questions
All
Junior Level
Mid Level
Senior Level
1.
What is the difference between frontend and backend?
2.
What is an API?
3.
What is Node.js?
4.
What is the difference between SQL and NoSQL?
5.
What is a database?
6.
What is Express.js?
7.
What is the HTTP protocol?
8.
What is a REST API?
9.
What is MongoDB?
10.
What is a backend in web development?
11.
How do you start a simple Express server?
12.
What is middleware in Express?
13.
How do you handle routes in Express?
14.
What is req and res in Express?
15.
How do you send JSON from an Express API?
16.
What is body-parser or express.json()?
17.
What is a 404 error and how do you handle it in Express?
18.
How do you create a POST route in Express?
19.
What are route parameters?
20.
What are query parameters?
21.
How do you connect Node.js to MongoDB?
22.
What is Mongoose?
23.
What is a schema in Mongoose?
24.
What is a model in Mongoose?
25.
How do you create and save a document in MongoDB?
26.
How do you find all documents in a collection?
27.
How do you find one document by ID?
28.
How do you update a document in MongoDB?
29.
How do you delete a document in MongoDB?
30.
What is .exec() in Mongoose?
31.
What is authentication?
32.
What is authorization?
33.
What is JWT?
34.
How do you hash a password in Node.js?
35.
How do you compare passwords?
36.
What is dotenv and why use it?
37.
What is CORS?
38.
What is helmet in Express?
39.
What is rate limiting?
40.
What is session-based auth vs token-based auth?
41.
How do you run a Node.js app in production?
42.
What is npm and what is package.json?
43.
How do you test an API?
44.
What is a 500 error?
45.
What is process.env?
46.
What is JSON?
47.
How do you deploy a Node.js app to production?
48.
What is the difference between PUT and PATCH?
49.
What is CRUD?
50.
What tools should a junior backend dev learn?
51.
What is the event loop in Node.js?
52.
Explain the difference between process.nextTick() and setImmediate().
53.
How does asynchronous programming work in JavaScript?
54.
What's the difference between == and === in JavaScript?
55.
What is the difference between var, let, and const?
56.
What are closures in JavaScript?
57.
Explain the concept of middleware in Express.js.
58.
How do you handle uncaught exceptions in Node.js?
59.
What are streams in Node.js?
60.
What is the difference between synchronous and asynchronous code in Node.js?
61.
How does MongoDB store data?
62.
What are the key differences between SQL and NoSQL databases?
63.
What is Mongoose and why is it used?
64.
How do you prevent NoSQL injection in MongoDB?
65.
Explain database indexing and its pros/cons.
66.
What is database normalization?
67.
When would you use transactions in MongoDB?
68.
Explain how pagination is implemented with MongoDB.
69.
What are aggregates in MongoDB?
70.
What is Prisma ORM?
71.
How does JWT authentication work?
72.
How do you implement role-based access control (RBAC)?
73.
What is CORS and how do you fix CORS issues?
74.
How do you securely store passwords in Node.js?
75.
What is the difference between session-based and token-based auth?
76.
What is rate limiting and why is it used?
77.
What is CSRF and how do you prevent it?
78.
How do you validate API inputs?
79.
What are HTTP status codes used for?
80.
How do you version an API?
81.
How do you test backend endpoints?
82.
What is mocking and why is it used in tests?
83.
How do you debug Node.js applications?
84.
What are the key differences between unit and integration tests?
85.
What is test coverage and why is it important?
86.
How do you write a test for an async function?
87.
What is a memory leak and how to detect it in Node.js?
88.
How do you test error handling?
89.
How do you organize your tests in a large project?
90.
What is the difference between describe() and it() in Jest?
91.
How do you handle large file uploads in Node.js?
92.
What is clustering in Node.js and why use it?
93.
How do you deploy a Node.js app to production?
94.
How do you secure environment variables?
95.
What is Docker and why is it used?
96.
What is CI/CD and how do you use it?
97.
How do you reduce bundle size in Node.js apps?
98.
How do you monitor errors in production?
99.
What are design patterns you’ve used in backend projects?
100.
How would you scale a Node.js backend app?
101.
What is event delegation in JavaScript, and how does it improve performance?
102.
Explain closures with a practical use case.
103.
What are Generics in TypeScript and when should you use them?
104.
How does the 'this' keyword behave differently in arrow functions?
105.
How does Type Inference work in TypeScript?
106.
What is the difference between interface and type in TypeScript?
107.
How would you handle deeply nested optional properties in TypeScript?
108.
Explain the module pattern and its benefit in JavaScript.
109.
How do you ensure immutability in JavaScript?
110.
Explain debounce vs throttle with examples.
111.
What is React Fiber, and why is it important?
112.
How would you handle memory leaks in React?
113.
What are React Server Components (RSC)?
114.
Compare getServerSideProps, getStaticProps, and getInitialProps in Next.js.
115.
When should you use App Router vs Pages Router in Next.js?
116.
How do you optimize Next.js SEO?
117.
How would you implement infinite scrolling in React?
118.
What is hydration mismatch in Next.js?
119.
How do you structure a large React app?
120.
Explain useEffect dependency behavior with examples.
121.
What is the difference between SQL and NoSQL? Why choose MongoDB?
122.
Explain how Prisma works with MongoDB.
123.
How do you design scalable REST APIs?
124.
How would you structure a Next.js API route for authentication?
125.
Explain CRUD operation using Prisma.
126.
How do you handle file uploads securely?
127.
What is middleware and where do you use it in full stack apps?
128.
How would you structure role-based access control (RBAC)?
129.
Explain connection pooling in MongoDB.
130.
How do you handle errors in async functions in Express/Next.js?
131.
JWT vs Sessions – which one to use and when?
132.
Explain how NextAuth.js works.
133.
How to prevent XSS and CSRF in full stack apps?
134.
How would you write unit tests for API routes in Next.js?
135.
How do you test React components?
136.
What is the role of middleware.ts in Next.js App Router?
137.
How to handle rate limiting in APIs?
138.
What is code splitting and why is it useful?
139.
How do you protect environment variables in deployment?
140.
How would you debug a production-level bug in Next.js?
141.
Explain the deployment process in Vercel.
142.
How do you implement CI/CD for a full stack app?
143.
How do you optimize images in Next.js?
144.
What is SSR and why is it better for SEO?
145.
How do you manage monorepos in large-scale apps?
146.
How do you handle cross-team collaboration in full stack projects?
147.
Explain your approach to solving performance bottlenecks.
148.
How do you make your app accessible (a11y)?
149.
How do you handle real-time features (e.g., chat)?
150.
What is your approach to mentoring junior developers?