Targeting

OpenAI is reportedly ramping up hiring this year, with plans to roughly double their employee count from around 4.5k employees to roughly 8k (according to reuters and the financial times, sources below). I've seen a lot more folks preparing for this loop in the workshops and interview prep discord I help with. Their system design can feel a little different from the classic FAANG style, so i'm posting all the insights I've gathered from folks that have recently gone through the loop for system design. ## Gotchas There can be system design in both the phone screen AND onsite. Some candidates have reported getting a system design round during both the phone screen, and during the onsite. Seems to vary by teams, as not everyone gets this, but it's common enough that you should be mentally prepared for it. You may need to think beyond backend infrastructure and reason about frontend implications too. A lot of backend-dev candidates go into system design interviews focused almost entirely on services, databases, queues, caches, scaling etc. At OpenAI, that might not be enough. Some of their design tasks probe whether you can think about how the product actually behaves from the user's point of view. If you've gone through Meta, then think of it as a combo of their product & infra system design round. The broader point is this: don't assume OpenAI system design is just about server-side plumbing. Real-time information processing & cognitive flexibility is especially important. A lot of candidates prepare system design by following a familiar sequence: requirements, rough numbers, API, data model, high-level design, deep dive, scaling, done. That approach can work in many interviews. But one of the OpenAI gotchas is that the interviewer may throw in new constraints, new product requirements, or a twist halfway through. So the interview isn't just testing whether you can produce a design. It's testing whether you can process new information in real time and adapt. That means you can't rely too heavily on memorized templates. You need to actually understand the design deeply enough to reshape it on the fly. You need to stay mentally flexible when the interviewer changes the target. ## Common Questions & Question Patterns Payments and money movement Design a payments pipeline where we forward to a payment processor, hold funds, then batch-settle daily. Webhooks and third-party integrations Design a webhook callback system for third-party integrations. Design a webhook delivery platform. CI/CD and developer workflows Design a multi-tenant CI/CD workflow system for many orgs. Design GitHub Actions from scratch. Real-time interaction and concurrency Design online chess. Design a Slack-like team messaging service. Big product systems Design Netflix. Design ChatGPT. --- Here's a walkthrough of a frequently asked question that shows the standard to aim for: Design a Slack-like MVP that a small team could realistically build and launch in 2 weeks. Hope this helps! ## Sources (OpenAI ramping up hiring) - https://www.ft.com/content/7ffea5b4-e8bc-47cd-adb4-257f84c8028b - https://www.reuters.com/business/openai-nearly-double-workforce-8000-by-end-2026-ft-reports-2026-03-21/