Optiver 2027 Online Assessment Exact Questions & Answers

The Optiver online assessment is a speed test, not a coding marathon. For the Quant Trader and Quant Researcher tracks it is a timed mental-math and probability battery, where finishing accurately under the clock matters more than knowing any one formula.

Software Engineers take a different shape entirely: long object-oriented simulation coding problems plus a CS quiz. This page covers both tracks.

For quant roles the Optiver online assessment is a multi-section battery on CodeSignal, about three hours total and often spread across days. It is deliberately long and anti-GPT, and frequently auto-rejects the moment you submit. The famous 80-in-8 mental-arithmetic screen — 80 questions in 8 minutes, no calculator — is a separate assessment from this battery; together they form the front gate.

The battery has four section types: Number Logic sequences (~15 questions / 25 min), Beat the Odds rapid probability (~30 questions / 45 min, ~90s each), and the Zap-N reaction and memory mini-games (45–60 min). The probability and sequence modules score +1 correct, −1 wrong, 0 skip with no going back — so a confident skip beats a blind guess.

How the OA differs by track

Timing and platform are role-dependent, so there is no single top-line number. The quant tracks share the mental-math battery; the SWE track is a different assessment built around long coding problems.

How to prepare

Prep is about reflexes, not coverage — work this order:

Rehearse the 80-in-8 in the exact format. Drill times tables to 19 and the common fraction–decimal conversions, and practise the missing-operand shape until reframing it is automatic.

Turn the Beat the Odds families into 30-second reflexes. The recurring shapes — cycle return times, gambler's-ruin ratios, symmetry “remove pairs” expectations, coupon-collector sums — repeat across years; drill each until it is instant.

Learn Number Logic's recurring tricks. Alternating odd/even sub-sequences, the two-term recurrence, product-of-previous and difference ladders cover most items; simplify any disguised constant first.

Practise the Zap-N reaction games cold. They reward calm and speed, not strategy — rehearse short-term recall, dual-task arithmetic, and a consistent risk policy on the balloon game.

If you're on the SWE track, grind long OOD simulations under a clock. Build a small class end to end in 75–90 minutes and force yourself to finish the last method with corner cases handled.