Jane Street Online Assessment

Jane Street's screen is built around probability, expected value, and mental math, not algorithmic coding. The first-round assessment is a short set of brain-teasers where your reasoning matters as much as the number; a separate quant-research round adds a live coding exercise, and trading-operations roles get an Excel-based task.

Trading & Research — Trader / QT / Research

Trader / QT / Researchwritten / HackerRank~4 questions / 30 min shown2017 -> 2025

A short, timed set of probability, expected-value, and mental-math questions (prime-sum parity, an optional-reroll dice game, a Bayesian coin re-flip, a two-urn posterior bet, plus counting and estimation). You explain your reasoning, not just the answer.

Trading & Research — Quant Research coding round

Quant Research coding roundlive coding1 problem shown2025

A second-round live coding exercise for quant-research candidates - a clean implementation problem (not LeetCode trickery), with follow-ups on efficiency and on shaping the code into a reusable library.

Jane Street OA — FAQ

What is the Jane Street online assessment?

Jane Street's screen is built around probability, expected value, and mental math, not algorithmic coding. The first-round assessment is a short set of brain-teasers where your reasoning matters as much as the number; a separate quant-research round adds a live coding exercise, and trading-operations roles get an Excel-based task.

What is the format of the Jane Street OA?

It runs as 2 tracks (Trader / QT / Research, Quant Research coding round). Trading & Research, Trading & Research — each timed, auto-graded where applicable.

How do I practice for the Jane Street online assessment?

Work the sample questions above (each with a full worked solution), then take the interactive Jane Street OA practice on QuantVault. For the full interview, see the Jane Street interview-questions set.