Software engineer interview questions (2026)

Software engineer interviews in 2026 typically span four rounds: a behavioural screen, a coding round, a system-design round (mid-level and up), and a team/values fit. Below are the questions that actually recur in each — and you can practice them in a free AI mock interview tailored to the exact job you're chasing.

Behavioural questions

• Tell me about a technically hard problem you solved. What made it hard?
• Describe a time you disagreed with a teammate on a design decision.
• Tell me about a project that failed or slipped. What did you learn?
• How do you decide what to build first when everything feels urgent?

Coding & problem-solving

• Walk me through your approach before you write any code.
• How would you handle this at 100× the input size?
• What edge cases would break your solution?

System design (mid-level and above)

• Design a URL shortener / rate limiter / news feed. Start with the requirements.
• Where are the bottlenecks, and how would you scale past them?
• What trade-offs did you make, and what would you change with more time?