Optiver Technical / Brain-Teaser Interview

The Optiver Technical / Brain-Teaser interview is stage 5 of 8 in the Optiver interview process, after the Cognitive Interview. Format: 60–75 min · Zoom whiteboard · with a researcher. The QR technical round: 3-4 problems mixing probability, conditional expectation, number theory, and brain-teasers, plus a Fermi estimation.

What the Technical / Brain-Teaser tests

QuantVault maps 189 practice problems to this round. By topic, the biggest groups are expectation (38), probability (38), coding (27), combinatorics (21); by difficulty, 20 easy, 101 medium and 68 hard. 85 of them were reported by candidates who interviewed at Optiver, most recently in Jun 2026.

Who takes this round: Quant Researcher candidates. See the full Optiver process and who takes each round.

How to prepare for the Technical / Brain-Teaser

• Talk through the setup before computing. A clean problem framing scores more than a fast but opaque answer.

Further reading: Fermi estimation questions · How quant superdays work · Behavioral questions at trading firms · Market-making game interview guide.

Question types in this round

The 5 largest question types in the Optiver Technical / Brain-Teaser practice set; across them the most common sub-topics are expected value, discrete probability, conditional probability, first-passage and stopping times, independence, symmetry. The questions themselves, with worked solutions, are in the round practice.

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