What does Jane Street ask in software engineer interviews?

Jane Street SWE interviews typically cover data structures and algorithms, system design, and behavioral questions. Candidates report coding rounds using LeetCode-style problems, plus architecture design and leadership questions for senior roles. LeakCode aggregates verified reports from 47+ candidates.

How many rounds does Jane Street have in its interview process?

The Jane Street interview process typically includes a recruiter screen, a phone/online assessment round, and 4-5 onsite or virtual interviews covering coding, system design, and behavioral competencies. The exact number of rounds varies by role and team.

How hard is it to get a job at Jane Street?

Jane Street is highly selective. Candidates report pass rates in the single digits for competitive engineering roles. Strong data structures fundamentals, system design ability, and clear communication are required to advance past initial screens.

What topics should I study for a Jane Street interview?

Based on aggregated Jane Street interview reports: arrays and hash maps, trees and graphs, dynamic programming, system design (distributed systems, databases, caching), and behavioral questions using the STAR method. LeakCode shows exactly which topics appear most often.

Does Jane Street ask LeetCode hard questions?

Interview difficulty at Jane Street varies. Coding rounds typically include medium to hard difficulty algorithmic problems. System design questions are open-ended and evaluated on depth of reasoning. Browse real Jane Street interview questions on LeakCode to see the actual difficulty distribution.

Jane Street Interview Questions (May 2026)

17 questions · 8 experiences · InterviewDB (21) · 1p3a (4)

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Software Engineer 24

Jane Street ML Performance Engineer Interview Experience

SWE Easy

1 upvote 11 replies

Question Details

This post was last edited by sycstudent on 2025-09-26 12:41 Basic Information: Last year of PhD program in the Midwest (hopefully) I contacted a recruiter from JS during the conference and scheduled an HR call and interview. Position: ML Performance Engineer I heard the second interview will test CUDA kernel performance. Does anyone have any good preparation materials to share? First Round Interview Results General

Coding Observing the posts on the forum, the first round of JS interviews seems to focus more on clarity and communication. The questions mainly involved implementing certain APIs, and weren't particularly difficult. Specific Questions: https://www.1point3acres.com/bbs/thread-1117783-1-1.html Class item has: optional buyer, string seller, int price, string item_name When item 5 is available for purchase, the buyer needs to be updated. Class DataStore: update, update the item information. When sold, the buyer changes from null to buyer_name. getAll,

return the information of all current items. First Question: Given a map (item_name -> Item) representing all items to be purchased, where each item contains the buyer's desired price and buyer_name.

Return map(item_name -> price) representing the final transaction price. The final transaction price is the lowest price among items with the same name in the DataStore (and also lower than the buyer's desired price). Update is also required. Update DataStore It's straightforward, just write it according to the logic. Second question: After all transactions end for the day, some transactions may fail (e.g., credit card issues). Handle the following two scenarios: Scenario 1: Alice, item A, transaction price 100, transaction time 1000, transaction fails -> item A, 100 re-open to sell. Bob, item A, transaction price 110, transaction time 1010, transaction succeeds -> refund 10, and item A, 110 re-open to sell. Cathy, item A, transaction price 105, transaction time 1020, transaction succeeds -> nothing happens, because the 110 item A returned by Bob is higher than Cathy's original transaction price. Scenario 2: Alice, item A, transaction price 100, transaction time 1000, transaction fails. David, item A, bid 110, transaction time 1020, transaction fails (because it was out of stock at the time) -> charge. 100. The requirement is to return charge and refund information (buyer_name, refund/charge_amount) to all buyers. The question isn't difficult; the basic logic is to scan the transaction records chronologically, record any failed transactions, and compare them with subsequent successful transactions. It's quite tedious and requires communication with the interviewer on several details. How to obtain the transaction records in chronological order? How to know David's situation in scenario 2—that is, how do we know there was a buyer but the transaction wasn't sold? Scenario 2: If David's transaction is before Alice's in the chronological order, is a charge still needed? The interviewer said no. My answer to this question wasn't perfect, so I was timed out. She then asked me to ask her about JavaScript. Overall feeling: Not particularly difficult, but communication and clarity are crucial. I don't know the result yet. I haven't been on the forum for a long time, and I've run out of points. I hope you guys can give me some! Please!

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Concurrency Ml Strings

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Jane Street Interview Process Overview

The Jane Street interview process typically includes a recruiter screen, one to two technical phone screens, and a 4-6 round on-site or virtual on-site loop. Each round serves a distinct calibration purpose: coding rounds measure correctness, code quality, and complexity reasoning; system design rounds measure architectural judgment at the appropriate level; behavioral rounds measure ownership, leadership scope, and collaboration. Reports tagged on LeakCode from 2024-2026 show Jane Street runs a calibrated process consistent with industry norms for companies of its tier.

Difficulty calibration: Jane Street coding rounds typically run medium difficulty with follow-up depth as the senior discriminator. System design rounds expect production-grade trade-off articulation at L4+ levels. Behavioral rounds expect quantified outcomes ("reduced p99 latency from 800ms to 120ms") rather than vague impact claims. The candidates who advance consistently demonstrate clear thinking out loud rather than perfect final answers.

How To Use Jane Street Question Reports

Real candidate-reported interview questions are a calibration tool, not a memorization target. Jane Street updates its question pool every 2-4 months; memorizing exact problems risks misleading you when the interviewer uses a variant. The high-leverage approach: identify the patterns that appear repeatedly in Jane Street reports, practice those patterns on similar (not identical) problems, and use the reports to understand the interviewer's typical follow-up depth.

Filter the questions above by round type, difficulty, and recency. Focus first on reports from the past 6-12 months; older reports may reference questions that have since rotated out of Jane Street's pool. Reports tagged with quantified difficulty and explicit round type are higher-signal than reports without those tags. The metadata filters help you build a focused study plan in 1-2 hours rather than 8-10 hours of unstructured browsing.

Common Jane Street Interview Mistakes

Reports tagged "no hire" at Jane Street consistently surface a few patterns: jumping into code without clarifying requirements, coding silently for extended periods, missing edge cases (empty input, single element, large input, overflow), producing working code the candidate cannot refactor when probed, and behavioral stories that use "we" instead of "I" diluting individual signal. Strong candidates explicitly avoid these patterns by following a consistent round template.

The single most predictive failure mode in recent reports: not asking clarifying questions. Interviewers are explicitly trained to weight this dimension. Strong candidates ask 3-5 clarifying questions even on problems that look obvious; weak candidates dive into implementation immediately. Strong candidates also verbalize their approach before writing code; weak candidates code in silence and lose the communication dimension of the round's calibration.