Duolingo Software Engineer tree traversal and graph coding assessment

After a conversation with a recruiter, I did a technical screening focused on a coding problem that felt very "standard" for interviews, something like a tree traversal. There was also a short follow-up about how I would improve the algorithm's efficiency. The interviewer kept the conversation moving. Although the core question wasn't unfamiliar, the optimization questions made me slow down and t…

Shared by a candidate · reported Apr 2026. Interview formats change; use it as a guide, not a script.