Top 20 Software Engineer Interview Questions
Master the most common technical and behavioral questions asked at top tech companies. Learn how to structure your coding responses perfectly.
Why these 20 questions keep coming back
Software engineering interviews at Google, Meta, Amazon, Microsoft, Netflix, and Apple are surprisingly repetitive. The same 20 questions — or close variants — cover more than 80% of the loops we've seen candidates run through in the last 12 months.
The reason is simple: interviewers need signal on a small number of skills — problem decomposition, data structure fluency, system trade-offs, communication, and ownership. A handful of questions test all of them.
Below are the exact prompts, why they're asked, and how to structure a response an interviewer can actually score.
10 technical questions you must be ready for
These are the coding and technical design questions that appear most often in on-site and virtual loops.
1. Two Sum and its variants
Almost every screen opens with an array or hash-map warm-up. Two Sum, Three Sum, and 'find pairs with a given difference' all test the same instinct: reach for a hash map before a nested loop.
Say the brute force out loud first, then improve it. Interviewers score the reasoning, not just the code.
2. Reverse a linked list
The single most-asked linked list question. Practice both iterative and recursive solutions and be ready to draw pointers on the whiteboard.
3. Validate a binary search tree
Tests recursion and invariants. The trap: many candidates compare only against parent nodes and miss the min/max range constraint.
4. Level-order traversal of a binary tree
A BFS classic. Use a queue, track depth per level, and mention how you'd adapt it for zig-zag order.
5. Longest substring without repeating characters
The canonical sliding-window problem. Master this pattern — it unlocks at least three other common questions.
6. Merge k sorted lists
Tests heaps and priority queues. Talk through the O(N log k) heap solution before writing code.
7. Number of islands
A grid-based BFS/DFS. Interviewers watch how cleanly you handle visited state and edge boundaries.
8. LRU cache
The most-loved design-in-code question. Doubly linked list plus hash map — practice writing it in under 25 minutes.
9. Design a URL shortener
The go-to system design prompt for mid-level candidates. Talk about ID generation, base62 encoding, cache tiers, and analytics.
10. Design a news feed
Senior-level favorite. Cover fan-out on write vs. read, ranking, and how you'd handle celebrity-scale users.
10 behavioral questions and how to structure them
Every technical loop includes at least one behavioral round. Use the STAR method — Situation, Task, Action, Result — and quantify the result whenever you can.
11. Tell me about yourself
Keep it under 90 seconds: current role, one signature project, why you're interviewing. Never recite your resume.
12. Tell me about a project you're proud of
Pick a project with a measurable outcome. Lead with the impact, then the technical decisions that produced it.
13. Describe a conflict with a coworker
Interviewers want to see empathy and ownership. Never blame the other person; show how you closed the loop.
14. Tell me about a time you failed
Choose a real failure with a clear lesson. 'I worked too hard' answers get you rejected.
15. How do you handle disagreement with your manager?
Show that you disagree with data, commit once a decision is made, and document the reasoning.
16. Tell me about a time you led without authority
Strong signal for senior roles. Focus on how you built alignment across teams that didn't report to you.
17. How do you prioritize competing deadlines?
Name your framework — RICE, MoSCoW, or your own — and give an example where prioritization changed mid-quarter.
18. What's your biggest weakness?
Pick a real weakness, then describe the concrete system you've built to manage it.
19. Why do you want to work here?
Tie the answer to a specific product, team, or engineering blog post. Generic answers hurt more than they help.
20. Do you have any questions for us?
Always yes. Ask about the team's biggest current challenge or how success is measured in the first 90 days.
How to practice these in the next 7 days
Reading the list is not the same as being able to answer under pressure. Block 45 minutes a day, pick two questions, and answer them out loud into an AI interview simulator that grades pacing, filler words, and structure.
Candidates who practice out loud — not just in their head — land offers at roughly twice the rate in our internal data.