OpenAI·Software Engineer·Technical Phone Screen
Jun 2026
Coding round at OpenAI for a software engineer role, pretty much one problem the whole time with a follow-up that kept expanding. The core question was path simplification but it grew into a full URL processing design discussion before I really saw it coming.
- Given a Unix-style absolute path string, write a function to simplify it to its canonical form.
- Given a stream of full URLs, how would you count how many times each normalized path appears, and how do you handle case sensitivity, trailing slashes, and percent-encoded segments?
- How would your design extend to support relative paths or symlinks, and what are the complexity implications?
“Stack-based approach, pretty standard if you've seen it before.” The rest of the author's notes on Software Engineer interview at OpenAI, Technical Phone Screen round, covers how they worked through the question, what the panel pushed back on, and what they would do differently.
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