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 | Strategy conversation. |
| System Design Strategy | 90 min | Multi-year AI strategy at company scale. |
| AI Infra Architecture Review | 60 min | Deep critique of an AI infra architecture. |
| Cross-Org Influence | 60 min | How you align research, engineering, and product. |
| Technical Vision (Writing) | Take-home | Strategy memo for an OpenAI-scale problem. |
| Hiring and Mentorship | 60 min | Staff hiring and growth stories. |
| Behavioral (Principal Scale) | 60 min | Company-level impact. |
| Senior Leader Round | 60 min | Vision, leadership style, fit. |
IC6 is the principal-level IC role. The bar is "sets AI infra strategy at company scale, hires and grows IC5s, and influences direction across research, engineering, and product".
The loop is almost entirely strategy, architecture judgment, influence, and writing. Coding is rare and limited to the phone screen.
What gets you hired is a clear, defensible technical point of view on where OpenAI's infra should go over multiple years, plus evidence you can align orgs and grow staff engineers.
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.
At OpenAI IC6 (Principal Engineer), the design portion of the loop is all AI engineering, not classical system design. The round is: AI Infra Architecture Review (60 min): Deep critique of an AI infra architecture.. Bar is multi-year architectural bets and cross-org technical strategy. You should be naming specific decisions you would defend in a roomful of senior engineers. Prepare in the AI Engineering track, not the System Design Problems track.
Principal bar. Multi-year bets, executive-level communication, cross-org influence, and growing Staff engineers. The behavioral rounds often outweigh technical-depth rounds in the final hiring decision at this level. Frame stories around safety-mindedness, mission alignment, and judgment under uncertainty about capabilities.
Write a real strategy memo for a problem you understand. Edit it twice. Read your own writing back the next morning. Aim for clear prose, specific recommendations, named trade-offs.