CrackingWalnuts
Checked 3 August 2026. OpenAI does not publish its interview structure. Everything on this page is commonly reported by candidates, so treat it as a guide rather than a specification.
| Round | Duration | What it tests |
|---|---|---|
| Phone Screen | 60 min | Practical coding plus background. |
| Practical Coding 1 | 60 to 90 min | Build a small library or service in real time. |
| Practical Coding 2 | 60 to 90 min | Different problem space. Often AI-flavored. |
| System Design (Light) | 60 min | AI infra or inference serving design. |
| Behavioral / Taste | 45 min | Why you built things the way you did. |
IC3 is the mid level. The bar is "writes practical code with good engineering taste, ramps up fast, and ships without hand-holding".
The OpenAI loop is fast and practical. Fewer algorithmic puzzles, more "build this small thing in 45 to 60 minutes and show me how you think".
The thing they are watching for is taste: clean names, sensible defaults, error shapes a caller can debug, and a clear "why this, not that" for every decision you make under time pressure.
Targeted guidance per round in this loop. Each section links to the matching track on the site. There is no shortcut list, the bar moves loop to loop, so build the pattern recognition and the stories from real practice.
Work the pattern templates until the recognition is instant. Trace one mock problem per pattern. Practice stating time and space complexity out loud before you write code.
OpenAI IC3 (Software Engineer, Mid) has one design round: System Design (Light) (60 min): AI infra or inference serving design.. Bar is a clean end-to-end design at modest scale, with a sensible API and one trade-off discussion. Pick problems from the track at the scale this loop tests and rehearse the structure: requirements, numbers, high-level design, data model, API, deep dive on one part, trade-offs.
Junior bar. You now have real production work. Stories should center on features you owned, bugs you debugged, and how you collaborated with senior engineers. Skip multi-team and multi-quarter scope; that comes at Senior. Frame stories around safety-mindedness, mission alignment, and judgment under uncertainty about capabilities.