Why Software Engineering Interviews in India Are a Different Beast
India produces over 1.5 million engineering graduates per year (AICTE 2025), and the competition for software roles at product companies, FAANG, and top IT services firms is intense. What differentiates the candidates who get offers isn’t just coding ability — it’s structured preparation across four domains: Data Structures & Algorithms (DSA), System Design, Object-Oriented Programming (OOP), and Behavioral rounds.
This guide covers the 50 most frequently asked SWE interview questions in India, categorised by round type, with key answers and preparation strategies.
Interview Round Structure at Indian Tech Companies
| Round | Companies That Use It | Focus Area |
|---|---|---|
| Online Assessment (OA) | All tier-1 companies | DSA (LeetCode-style) |
| Technical Round 1–2 | All companies | DSA + problem solving |
| Technical Round 3 | FAANG, product MNCs | System Design |
| HR / Behavioural | All companies | Communication, culture fit |
| Hiring Manager Round | Senior roles | Strategy, team fit |
Section 1: Data Structures & Algorithms (DSA) — Most Asked 20
ARRAYS & STRINGS
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1. Two Sum / Three Sum problem
2. Maximum subarray (Kadane’s Algorithm)
3. Rotate array / matrix
4. Longest substring without repeating characters
5. Valid parentheses (stack-based)
LINKED LISTS
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6. Reverse a linked list (iterative + recursive)
7. Detect cycle in a linked list (Floyd’s algorithm)
8. Merge two sorted linked lists
9. Find the middle of a linked list
TREES & GRAPHS
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10. Binary tree traversals (inorder, preorder, postorder)
11. Level-order traversal (BFS)
12. Lowest common ancestor (LCA)
13. Validate a binary search tree
14. BFS and DFS on a graph
15. Detect cycle in a directed graph
DYNAMIC PROGRAMMING
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16. Fibonacci (top-down vs. bottom-up)
17. Coin change problem
18. Longest common subsequence
19. 0/1 Knapsack problem
20. Climbing stairs
> 📌 India Prep Tip: LeetCode Top 150 is the gold standard for DSA prep. Target Easy + Medium questions first. For FAANG/product roles, solve at least 200+ problems (50+ Medium).
Section 2: System Design — Most Asked 10
These questions appear in Round 3+ at product companies and senior roles (3+ years experience):
21. Design a URL shortener (like bit.ly)
22. Design a scalable notification system
23. Design an e-commerce product page (like Flipkart/Amazon)
24. Design a rate limiter
25. Design a chat application (like WhatsApp)
26. Design a ride-sharing service (like Ola/Uber)
27. Design a content delivery network (CDN)
28. Design a search autocomplete system
29. Design a distributed cache (like Redis)
30. Design a job scheduling system
System Design Framework (for Every Question)
STEP 1: Clarify Requirements (5 min)
→ Functional requirements (what it does)
→ Non-functional requirements (scale, latency, availability)
STEP 2: Estimate Scale (2 min)
→ Daily active users, reads/writes per second, storage needs
STEP 3: High-Level Design (8 min)
→ Draw core components: client, API gateway, services, DB, cache
STEP 4: Deep Dive (15 min)
→ Focus on 1–2 critical components the interviewer cares about
STEP 5: Trade-offs (5 min)
→ What did you sacrifice? Consistency vs availability? Read vs write optimised?
Section 3: OOP and Core Concepts — 10 Questions
31. What are the 4 pillars of OOP?
→ Encapsulation, Abstraction, Inheritance, Polymorphism
32. Explain SOLID principles (one line each)
→ S: Single Responsibility | O: Open/Closed | L: Liskov Substitution
→ I: Interface Segregation | D: Dependency Inversion
33. What is the difference between abstract class and interface?
34. Explain method overloading vs. overriding
35. What is a design pattern? Name 3 common ones.
→ Singleton, Factory, Observer
36. What is the difference between stack and heap memory?
37. Explain garbage collection in Java/Python
38. What is a REST API? Difference between PUT and PATCH?
39. Explain microservices vs. monolithic architecture
40. What is time complexity of HashMap operations? When does it degrade?
Section 4: Behavioural & HR Questions — 10 Questions
41. “Tell me about a time you delivered a project under tight deadlines.”
42. “Describe a situation where you had a technical disagreement with a peer.”
43. “Tell me about the most complex technical problem you’ve solved.”
44. “How do you handle technical debt while meeting business timelines?”
45. “Why do you want to leave your current company?” (mid-level)
46. “What’s your approach to code reviews?”
47. “Tell me about a time you had to learn a new technology quickly.”
48. “How do you prioritise between multiple urgent bugs?”
49. “What does good documentation mean to you?”
50. “Where do you see your engineering career in 5 years?”
India Company-Specific Preparation
| Company Type | Top DSA Focus | Additional Focus |
|---|---|---|
| TCS / Infosys / Wipro | Aptitude + basic DSA | Communication, project discussion |
| Flipkart / Swiggy / Zomato | Medium-Hard DSA + System Design | Product thinking, scalability |
| Google India / Microsoft | Hard DSA + System Design + Behavioural | STAR stories, leadership principles |
| Razorpay / CRED / Meesho | Medium DSA + API design + culture | Ownership, product curiosity |
30-Day DSA Preparation Plan
WEEK 1: Arrays, Strings, Hash Maps, Two Pointers
WEEK 2: Linked Lists, Stacks, Queues, Trees
WEEK 3: Graphs (BFS/DFS), Dynamic Programming (Basic)
WEEK 4: Advanced DP, System Design basics, Mock Interviews
DAILY: 3–4 LeetCode problems (1 Easy + 2 Medium)
DAILY: 30 min System Design reading/watching
WEEKLY: 2 full mock interviews
Key Takeaways
- Most Indian SWE interviews test DSA, System Design, OOP, and Behavioural rounds
- Master LeetCode Top 150 as a baseline — add more for FAANG
- System Design is critical for 3+ years experience — use the 5-step framework
- SOLID principles, design patterns, and REST are non-negotiable core knowledge
- Prepare 5–6 STAR stories for behavioural rounds — one for each key theme
References
- AICTE Engineering Graduate Report 2025 — [aicte-india.org](https://www.aicte-india.org)
- Leetcode Top Interview Questions — [leetcode.com/problem-list/top-interview-questions](https://leetcode.com)
- System Design Primer (GitHub) — [github.com/donnemartin/system-design-primer](https://github.com/donnemartin/system-design-primer)
- Glassdoor India: Tech Interview Questions 2025 — [glassdoor.co.in](https://www.glassdoor.co.in)
- GeeksforGeeks DSA Interview Guide — [geeksforgeeks.org](https://www.geeksforgeeks.org)