Fresher SDE — questions you'll face anywhere

Software Engineer (generic) — likely questions

1. Walk me through a project you're proud of.

STAR. Lead with the problem and impact, then the stack and your specific contribution. Pre-empt the obvious follow-ups: why this design, what you'd change now.
2. What happens when you type a URL and press Enter?

DNS resolution → TCP/TLS handshake → HTTP request → server response → browser parses HTML, fetches assets, renders. Hit the layers you know best in more depth.
3. Explain time and space complexity of your solution.

State Big-O for both, justify it from the loops/data structures, and mention the trade-off you chose (e.g. hash map for O(1) lookups at O(n) space).
4. Difference between an array and a linked list?

Array = contiguous, O(1) index, costly insert/delete mid-list; linked list = nodes+pointers, O(1) insert/delete given the node, O(n) access. Pick based on access vs mutation pattern.
5. How do you find a cycle in a linked list?

Floyd's tortoise-and-hare: two pointers, slow by 1 and fast by 2; they meet iff there's a cycle. O(n) time, O(1) space. Be ready to find the cycle start.
6. Tell me about a time you debugged something hard.

Describe the symptom, how you isolated it (logs, bisecting, reproducing), the root cause, and the fix. Emphasise the systematic approach, not luck.
7. Where do you see yourself growing technically?

Name a concrete direction (backend/distributed systems, ML, frontend craft) and one thing you're already doing about it — a course, a side project, contributions.