Jane Street Interview Questions
Practice the exact questions companies are asking right now.
Design exchange–trading system message flow
Design the message contract and flow between a firm's trading system (OMS/EMS) and an external exchange. Assume: - The trading system sends orders and...
Validate order book data across multiple databases
Assume your organization stores order book–related data in multiple databases (e.g., one for raw exchange messages, one for normalized orders, one for...
Sort trade executions into a canonical order
You are building a small component in a trading system that consumes trade execution records from an upstream feed. The records may arrive out of orde...
Solve probability and game-theory puzzles
You are interviewing for a quant trading internship. Answer the following probability / game-theory puzzles. 1) Two bottles, add/remove balls (100 rou...
Solve queue switch and coin change puzzles
This entry contains two separate interview-style quantitative/algorithmic questions. --- 1. Queue switching decision problem You are standing in a sin...
Analyze trading RFQ competitiveness data
RFQ Competitiveness Analysis in Excel You are given an Excel file containing a few months of trading RFQ (request-for-quote) data for a sales & tradin...
Calculate win chance in three-player dice game
Probability of Winning with Rerolls on Ties Setup - Three players: A (you), B, and C. - A fair six-sided die is used. - B and C have already rolled an...
Use Excel formulas to compute haircuts
You are given an Excel worksheet with columns such as Asset, Market Value, and Haircut %. Using only cell references (no copy-paste of numeric values)...
Design sequential reveal classification and policy
FashionMNIST: Row-wise Reveal Evaluation, Reward-Optimal Masking, Augmentation, and Early Exit Context You have a trained CNN classifier for FashionMN...
Implement Connect Four with bottom push-up
Implement a Connect Four variant where when a player inserts a disc into a column, the disc moves to the bottom cell of that column and pushes all exi...
Answer why Jane Street
HR Screen Behavioral Question: Why Jane Street? You are interviewing for a Software Engineer role. In 60–90 seconds, explain: 1. Why Jane Street speci...
Implement compiler for custom language
Design and implement a simple compiler/interpreter Goal Design and implement a small compiler/interpreter for a bespoke toy language in your preferred...
Predict future time-series values
End-to-End Time-Series Forecasting (PyTorch) Context You are given one or more regularly sampled numeric time series and optional exogenous covariates...
Calculate dice game win probability
Dice Game With Tie Rerolls: Probability You Eventually Win Context - Three players each roll a fair standard 6-sided die. - The highest roll wins. - I...
Design an end-to-end training framework
Design an End-to-End Time-Series Forecasting Framework (PyTorch) You are tasked with designing a production-grade, end-to-end framework for training a...
Build a time-series forecasting model
Forecast the Next H Steps for Time Series Context You are given one or more time series with timestamps and numeric targets (e.g., demand, returns, se...
Design and implement a tiny language runtime
Minimal Imperative Language — Design and Implementation Task Context You are asked to design and implement a minimal imperative language and its tooli...