Sefism is free for learners. We are here to help you grow, one step at a time.Join for free
Sefism.
FintechBank, telecom or listed firm

Jane Street

Quantitative trading firm that builds its own trading systems, largely in OCaml.

Not known3 stage process documentedFounded 2000
Headquarters

New York, New York, United States

Headcount

1,000 to 5,000

1,000 to 4,999 people
Work model

Not known

Hiring

Not known

Not enough signal to say. Check the careers page directly.
Where to apply
Careers pageWebsite

Ask for a referral to Jane Street

A referral only means something if the person giving it can actually speak to your work. I will refer you where I know someone on the inside and your profile genuinely fits the role, and I will tell you plainly when I cannot. Either way you get an answer, and a straight one.

  • I read every request. A reply takes a few days, sometimes longer.
  • I will not refer someone for a role their profile does not fit. It wastes your time and costs me the contact.
  • Where I cannot refer you, I will say why, and point you at the way in that does work.
  • Nothing you send here is shared with anyone without you agreeing to it first.

If you found the opening, paste it. It tells me which team you mean.

A Drive, Dropbox or personal-site link is fine. Make sure it opens without a request for access, or I cannot read it.

At least a short paragraph. This is what I would be putting my name behind, so specifics beat adjectives.

Comma separated, up to six. Things you would be happy to be tested on.

Open internships

How they hire

This describes software engineering roles; trading and research roles follow a different, more quantitative process. Interviews run only on weekdays during local business hours.

  1. 1

    Remote technical interview

    Official +2
    Live codingRemote

    A coding and algorithms problem worked through with Jane Street software engineers in a shared online editor over a phone or Zoom call.

    CodingAlgorithms
  2. 2

    Final-round interviews in an office

    Official +2
    On-site testIn person

    A day of in-person interviews in New York, London or Hong Kong, run much like the remote round and entirely technical. Jane Street books and pays for travel and hotel.

    CodingCollaboration
  3. 3

    Outcome

    Official
    Offer

    Jane Street aims to give the result within about a week, occasionally up to ten days in busy periods.

What comes up

Recurring themes from candidate accounts, not a question bank. Nobody is served by leaked question lists, least of all you in the interview.

  • Open-ended problems in several parts

    Official +1

    Problems are chosen to have multiple plausible angles and grow in stages, so the path you take matters more than the final snapshot of code.

  • Real code in a language you know well

    Official +1

    You write working code, not pseudocode, in any language. Jane Street asks candidates not to pick OCaml just to impress, and says no OCaml or finance knowledge is required.

  • Clarity and collaboration

    Official

    Interviewers judge whether they would like to work with you: be nice, be clear, know your language and be honest about what you do not know.

  • Programming, not maths puzzles

    Official

    General software engineering interviews focus on programming and do not include maths or probability questions.

Worth reading before you apply

From the Sefism resource library, matched to the rounds above.

Platform
Design Gurus Problem Set

A browsable practice library of coding problems that can be filtered by pattern, data structure, difficulty and company, so you can drill exactly the weakness you found this week. Patterns include two pointers, sliding window, hash maps, stacks, backtracking and greedy algorithms, with company filters for Google, Meta, Microsoft, Amazon, Oracle and LinkedIn. Free to browse, with an in-browser editor and solutions.

  • Job search
  • DSA
Design Gurus · Interview Prep · Ongoing
FreeDetails
Course
Grokking 75: Top Coding Interview Questions

A course built around 75 coding interview questions chosen for coverage across 18 topic areas, from arrays and sliding window to graphs, backtracking, dynamic programming and tries. Each question has a step-by-step algorithm, a walkthrough and complexity analysis, with solutions in six languages. It suits candidates with a few weeks before an interview who need a balanced, finite problem set rather than an endless list.

  • Job search
  • DSA
Design Gurus · Interview Prep · 3 to 4 weeks · Intermediate
SubscriptionDetails
Guide
Design Gurus Newsletter

A free newsletter of short, focused posts on system design and problem solving, from the team behind the Grokking courses. Recent posts cover company interview processes (such as OpenAI and Anthropic roles), the most asked mobile system design questions and preparation plans, each linking to a fuller article on the blog. It suits engineers who want a steady, low-effort way to keep system design and interview topics fresh between deeper study sessions.

  • System design
  • DSA
Design Gurus · System Design
FreeDetails
Guide
GeeksforGeeks

A very large site of articles on data structures, algorithms and core CS subjects such as operating systems, DBMS, computer networks and OOP, usually with code in several languages, plus practice problems and paid courses. It is handy for revising a university topic or finding a worked example of a specific algorithm. Quality varies because much is community written, so cross-check anything surprising against a textbook or official documentation.

  • DSA
  • CS fundamentals
  • Databases
GeeksforGeeks · Other · Ongoing reference
FreeDetails
Roadmap
Sefism CS Core Subjects Roadmap

An eight-stage roadmap through the core CS subjects: how a computer runs a program, OOP and design, operating systems, computer networks, database theory and internals, software engineering and theory, finished with a systems project such as a shell, an HTTP server or a tiny database. It suits CS students and self-taught developers filling the same gaps, and favours understanding shown in working code over memorised answers.

  • DSA
  • CS fundamentals
  • Databases
Sefism · Other · About 216 hours, 22 to 46 weeks · Beginner
FreeDetails
Course
Grokking Database Fundamentals for Tech Interviews

A text-based course on how databases work underneath: storage and page layout, indexing, transactions and ACID, concurrency control, partitioning and sharding, replication and consistency, consensus and leader election, recovery, and the main NoSQL families. It ends with case studies designing the databases behind Quora, TikTok, Airbnb and Snapchat. It suits engineers who want their database choices in system design answers to be defensible rather than hand-waved.

  • System design
  • Databases
  • Backend
  • Job search
Design Gurus · System Design · 2 weeks · Beginner
SubscriptionDetails
Browse the whole library

What it pays

Nothing collected for this company yet, and nothing worth guessing at. A made-up range is worse than no range because people negotiate against it.

Add to the Jane Street page

This library is only as good as what people who have been through it are willing to share. Most of these companies have no hiring process documented anywhere, and one account of what the rounds actually were is worth more than anything I can research from the outside.

What are you adding?

This decides how the claim is labelled on the page. Only someone representing the company can produce an “official” label, and I check that separately.

Year and month.

Comma separated topics, not the questions themselves.

Round by round is ideal: what each one was, how long, remote or in person, and what it covered.

Credit

Anonymous is the default. If you keep it anonymous, nothing identifying you reaches the page: it is published as a candidate account and your name stays with me. Never send anything covered by an NDA, and never send a take-home or a question paper.

What they build on

OCamlFPGA

Universities they recruit from

No sourced university links yet. A campus drive, a career fair appearance or an internship partnership is what puts a university here.

Add to the Jane Street page

This library is only as good as what people who have been through it are willing to share. Most of these companies have no hiring process documented anywhere, and one account of what the rounds actually were is worth more than anything I can research from the outside.

What are you adding?

This decides how the claim is labelled on the page. Only someone representing the company can produce an “official” label, and I check that separately.

Year and month.

Comma separated topics, not the questions themselves.

Round by round is ideal: what each one was, how long, remote or in person, and what it covered.

Credit

Anonymous is the default. If you keep it anonymous, nothing identifying you reaches the page: it is published as a candidate account and your name stays with me. Never send anything covered by an NDA, and never send a take-home or a question paper.

How to actually get seen

Jane Street publishes a written walkthrough and a mock interview video; practise with a timer, talking out loud and writing complete code in your strongest language.

Sources

Whole profile last checked 2026-09-22.

Interviewed at Jane Street? Fill in what changed.

Processes change, rounds get added, tests get replaced. If what you went through was different from what is on this page, tell me and I will update it.

Want me to refer you here?

Send me the role, your CV and a few honest paragraphs on why you fit it. Where I know someone inside and your profile matches, I will make the introduction. Where I cannot, I will tell you why and point you at the route that does work. You get an answer either way.

Ask for a referral to Jane Street

A referral only means something if the person giving it can actually speak to your work. I will refer you where I know someone on the inside and your profile genuinely fits the role, and I will tell you plainly when I cannot. Either way you get an answer, and a straight one.

  • I read every request. A reply takes a few days, sometimes longer.
  • I will not refer someone for a role their profile does not fit. It wastes your time and costs me the contact.
  • Where I cannot refer you, I will say why, and point you at the way in that does work.
  • Nothing you send here is shared with anyone without you agreeing to it first.

If you found the opening, paste it. It tells me which team you mean.

A Drive, Dropbox or personal-site link is fine. Make sure it opens without a request for access, or I cannot read it.

At least a short paragraph. This is what I would be putting my name behind, so specifics beat adjectives.

Comma separated, up to six. Things you would be happy to be tested on.

Add to the Jane Street page

This library is only as good as what people who have been through it are willing to share. Most of these companies have no hiring process documented anywhere, and one account of what the rounds actually were is worth more than anything I can research from the outside.

What are you adding?

This decides how the claim is labelled on the page. Only someone representing the company can produce an “official” label, and I check that separately.

Year and month.

Comma separated topics, not the questions themselves.

Round by round is ideal: what each one was, how long, remote or in person, and what it covered.

Credit

Anonymous is the default. If you keep it anonymous, nothing identifying you reaches the page: it is published as a candidate account and your name stays with me. Never send anything covered by an NDA, and never send a take-home or a question paper.

Work with me

Stuck on something specific?

Writing only gets you so far. If you want an answer to your situation rather than the general case, book a session and we will work through it together. Sessions are free for approved Sefism members, and a few slots open each week.

Book a free sessionSee all services

Follow along

New writing, resources and project ideas land here first.