ZorixOS
11+ Jane Street questions

Jane Street interview questions and how to prepare

The questions candidates report from Jane Street interviews, sorted by how often they come up, with difficulty and topics, plus original practice written in Jane Street's interview style.

Practice Jane Street questions free All companies

ZorixOS tracks 11 community-reported Jane Street interview questions, drawn from an open-source dataset of real interview reports and sorted by how frequently each one comes up. Every question links to its source. Alongside them are 78 original ZorixOS practice questions written in Jane Street's known interview style (not claimed as asked at Jane Street), so you can rehearse the real format. Practice any of them out loud in a free AI mock interview tuned to Jane Street.

Updated July 2026

Jane Street interview questions candidates report

Community-reported from real Jane Street interviews (open-source dataset), most-asked first. Showing 11. Each links to its source.

  1. Count Common Words With One Occurrence
    ArrayHash TableStringCounting
    Easy100% asked
  2. Walking Robot Simulation
    ArrayHash TableSimulation
    Medium93% asked
  3. Minimum Time to Make Array Sum At Most x
    ArrayDynamic ProgrammingSorting
    Hard91% asked
  4. Add Two Integers
    Math
    Easy90% asked
  5. Stream of Characters
    ArrayStringDesignTrie
    Hard83% asked
  6. Add Strings
    MathStringSimulation
    Easy73% asked
  7. Design a Text Editor
    Linked ListStringStackDesign
    Hard73% asked
  8. Evaluate Division
    ArrayStringDepth-First SearchBreadth-First Search
    Medium73% asked
  9. Longest Common Prefix
    StringTrie
    Easy57% asked
  10. Number of Orders in the Backlog
    ArrayHeap (Priority Queue)Simulation
    Medium57% asked
  11. Trapping Rain Water
    ArrayTwo PointersDynamic ProgrammingStack
    Hard57% asked

Practice questions in Jane Street's style

Original ZorixOS questions written the way Jane Street interviews, so you rehearse the real format. Not claimed as asked at Jane Street.

  1. Design a system to monitor real-time trading volumes across several asset classes (equities, options, futures) for Jane Street's internal trading desks, ensuring low latency and high availability. Consider how to handle bursts of activity and potential network partitions.

    Software EngineerSystem DesignTests: Evaluates the candidate's ability to design scalable, fault-tolerant distributed systems relevant to high-frequency trading environments.

  2. You've observed a sudden 10% drop in the liquidity of a specific options contract Jane Street is actively trading. What are your immediate debugging steps to identify the root cause, considering potential issues with market data feeds, order routing, or internal risk management systems?

    Software EngineerDebuggingTests: Assesses systematic problem-solving skills and understanding of trading system components under pressure.

  3. Implement a function in Python that takes an array of trade executions and returns the best bid/ask spread for a given symbol over a specific time window. Assume trade executions are not necessarily sorted by time. Optimize for performance.

    Software EngineerCoding ReasoningTests: Tests coding proficiency, algorithmic thinking, and performance optimization in a financial data context.

  4. Jane Street is expanding its algorithmic trading strategies into new, less liquid markets. How would you architect a new trading strategy execution engine that can be easily adapted to different market structures and regulatory environments while maintaining performance and safety?

    Software EngineerSystem DesignTests: Probes architectural design skills for flexibility and extensibility in complex, evolving trading landscapes.

  5. Imagine a scenario where a Jane Street trading system is experiencing intermittent latency spikes. How would you approach diagnosing the problem? What tools and techniques would you use to pinpoint the bottleneck, considering the distributed nature of trading infrastructure?

    Software EngineerDebuggingTests: Evaluates troubleshooting methodology in a high-stakes, distributed systems environment.

  6. Write a SQL query to find the top 5 most profitable trading pairs on Jane Street's platform yesterday, considering commissions and execution slippage. Assume tables `trades` (trade_id, symbol, execution_price, quantity, timestamp) and `market_data` (symbol, bid_price, ask_price, timestamp).

    Data ScientistSQLTests: Tests SQL proficiency and ability to derive business insights from financial data.

72+ more Jane Street-style questions are in the free library, each practiceable live with adaptive follow-ups and an honest scorecard. Start free.

Keep exploring

Can you answer these out loud, under Jane Street-style follow-ups?

The ZorixOS AI interviewer runs a Jane Street-tuned mock interview: it asks these kinds of questions, digs into your answers, and scores you against a real hiring bar. Your first one is free.

Start your Jane Street mock interview
Jane Street Interview Questions (2026) | ZorixOS