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Mar 22, 2025 | 9 min read

Advent of Hardcaml

Advent of Code is an annual Advent calendar featuring small programming puzzles created by Eric Wastl, which has been running every December since 2015. Being...

By: Anish Singhani
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Jan 24, 2025 | 6 min read

How we accidentally built a better build system for OCaml

A “build system” is one of the most important tools in a developer’s toolbox. Roughly, it figures out how to create runnable programs from a...

By: Andrey Mokhov
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Oct 04, 2024 | 8 min read

Developer education at Jane Street

Like most places, Jane Street largely teaches developers through a kind of apprenticeship model. A team matching process tries to thoughtfully match new devs to...

By: Aaron Bauer
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Aug 29, 2024 | 9 min read

ICFP 2024

It’s no secret that Jane Street is an active participant in the programming language community, and we’re excited to be attending ICFP 2024, the International...

By: Nailen Matschke
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Aug 26, 2024 | 15 min read

What the interns have wrought, 2024 edition

We’re once again at the end of our internship season, and it’s time do our annual review of what the interns achieved while they were...

By: Yaron Minsky
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Jul 22, 2024 | 3 min read

Visualizing piecewise linear neural networks

Neural networks are often thought of as opaque, black-box function approximators, but theoretical tools let us describe and visualize their behavior. In particular, let’s study...

By: Ricson Cheng
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Sep 12, 2023 | 10 min read

What the interns have wrought, 2023 edition

We’re once again at the end of our internship season, and it’s my task to provide a few highlights of what the dev interns accomplished...

By: Yaron Minsky
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Sep 01, 2023 | 18 min read

Oxidizing OCaml: Data Race Freedom

OCaml with Jane Street extensions is available from our public opam repo. Only a slice of the features described in this series are currently implemented....

By: Max Slater
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Jul 06, 2023 | 2 min read

We're sponsoring SoME3

Jane Street is excited to announce our sponsorship of SoME3, Grant Sanderson and James Schloss’s third Summer of Math Exposition. SoME is a contest that...

By: Craig Falls
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Jun 21, 2023 | 16 min read

Oxidizing OCaml: Rust-Style Ownership

OCaml with Jane Street extensions is available from our public opam repo. Only a slice of the features described in this series are currently implemented....

By: Max Slater
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May 26, 2023 | 15 min read

Oxidizing OCaml: Locality

OCaml with Jane Street extensions is available from our public opam repo. Only a slice of the features described in this series are currently implemented....

By: Max Slater
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Apr 14, 2023 | 10 min read

Building reproducible Python environments with XARs

Our traders and researchers love Python for its agility and for its huge open-source ecosystem, especially when it comes to machine learning. But the heavy...

By: Pavel Senchanka
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Jan 09, 2023 | 14 min read

What if writing tests was a joyful experience?

At Jane Street we use a pattern/library called “expect tests” that makes test-writing feel like a REPL session, or like exploratory programming in a Jupyter...

By: James Somers
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Dec 07, 2022 | 8 min read

Accelerating zk-SNARKs - MSM and NTT algorithms on FPGAs with Hardcaml

In 2022 a consortium of companies ran an international competition, called the ZPrize, to advance the state of the art in “zero-knowledge” cryptography. We decided...

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Nov 23, 2022 | 4 min read

Visualizing information propagation in markets

The Dojima rice market, established around 1716, is widely considered to be the world’s first organized futures exchange. Instead of directly exchanging money for rice...

By: Ricson Cheng
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Nov 17, 2022 | 17 min read

Computations that differentiate, debug, and document themselves

One of the problems we wrestle with at Jane Street is how to understand and manage the costs associated with the positions we hold: things...

By: Aditya Srinivasan
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Aug 30, 2022 | 1 min read

Introducing the Jane Street Graduate Research Fellowship

We are excited to announce the launch of the Jane Street Graduate Research Fellowship!

By: Emily Berger
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Aug 25, 2022 | 10 min read

What the interns have wrought, 2022 edition

We’re once again at the end of our internship season, and it’s my task to provide a few highlights of what the interns accomplished while...

By: Yaron Minsky
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Featured Reads


  • Read more

    Posts about interviewing at Jane Street and our internship program


  • Read more

    Using ASCII waveforms to test hardware designs


  • Read more

    Finding memory leaks with Memtrace

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© Copyright 2015-2025 Jane Street Group, LLC. All rights reserved. Services are provided in the U.S. by Jane Street Capital, LLC and Jane Street Execution Services, LLC, each of which is a SEC-registered broker dealer and member of FINRA (www.finra.org). Regulated activities are undertaken in Europe by Jane Street Financial Limited, an investment firm authorized and regulated by the U.K. Financial Conduct Authority, and Jane Street Netherlands B.V., an investment firm authorized and regulated by the Netherlands Authority for the Financial Markets (Autoriteit Financiële Markten), and in Hong Kong by Jane Street Hong Kong Limited, a regulated entity under the Hong Kong Securities and Futures Commission (CE No. BAL548). Each of these entities is a wholly owned subsidiary of Jane Street Group, LLC. This material is provided for informational purposes only and does not constitute an offer or solicitation for the purchase or sale of any security or other financial instrument. | Jane Street and the concentric circle mark are registered trademarks of Jane Street.

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