Full Stack Interview Prep Dashboard
Mid-Level Developer Interview Prep • JavaScript, React, Node.js, SQL/NoSQL & System Design
Overall Progress0 / 34 (0%)
JS / TS Fundamentals
1. Explain closures with an example. Why do they matter in practice?
JS / TS Fundamentals
2. What's the difference between == and ===? When would you deliberately use ==?
JS / TS Fundamentals
3. Explain the event loop: call stack, microtasks, macrotasks.
JS / TS Fundamentals
4. What are the benefits of TypeScript over plain JavaScript in a team setting?
JS / TS Fundamentals
5. Explain Promise.all vs Promise.allSettled vs Promise.race.
Frontend (React)
6. What problem do React hooks solve compared to class components?
Frontend (React)
7. Explain the difference between useEffect and useLayoutEffect.
Frontend (React)
8. How does React's reconciliation (virtual DOM diffing) work at a high level?
Frontend (React)
9. When would you reach for useMemo/useCallback, and when is it actually unnecessary?
Frontend (React)
10. How do you manage global state in a mid-size React app — Context API vs Redux/Zustand?
Backend (Node.js / APIs)
11. How does Node.js handle concurrency despite being single-threaded?
Backend (Node.js / APIs)
12. REST vs GraphQL — when would you pick one over the other?
Backend (Node.js / APIs)
13. How do you design a rate limiter for a public API?
Backend (Node.js / APIs)
14. Walk through how you would structure error handling in an Express (or similar) API.
Backend (Node.js / APIs)
15. How do you handle authentication vs authorization in a full-stack app?
Databases
16. When would you choose SQL vs NoSQL for a new feature?
Databases
17. Explain database indexing and its trade-offs.
Databases
18. What is a database transaction, and what do ACID properties mean?
Databases
19. How would you design a schema for a many-to-many relationship (e.g., users and roles)?
Databases
20. What's the N+1 query problem, and how do you avoid it?
System Design
21. Design a URL shortener. What are the key components?
System Design
22. How would you scale a Node.js API that's suddenly getting 10x traffic?
System Design
23. How do you approach caching in a full-stack app — what layers exist?
Testing & DevOps
24. What's your testing strategy across a full-stack app — unit, integration, E2E?
Testing & DevOps
25. Walk through a CI/CD pipeline you've set up or worked with.
Behavioral
26. Tell me about a time you had to work across the full stack to debug a production issue.
Behavioral
27. Describe a time you had to make a trade-off between shipping fast and writing clean/scalable code.
Behavioral
28. How do you decide whether a feature belongs in the frontend or backend?
Behavioral