Jane Street Tech Blog

Using group theory to explore the space of positional encodings for attention

12 days ago

Attention is a computational primitive at the core of modern language models...

Can you reverse engineer our neural network?

2 months ago

A lot of “capture-the-flag” style ML puzzles give you a black box...

Results from the Advent of FPGA Challenge

3 months ago

At the end of last year, we decided to try something new...

I design with Claude more than Figma now

3 months ago

For a long time I was skeptical of LLMs—whenever I reached for...

Fun with Algebraic Effects - from Toy Examples to Hardcaml Simulations

4 months ago

I recently ported the Hardcaml_step_testbench library, one of the libraries that we...

Getting from tested to battle-tested

5 months ago

Advent of FPGA — A Jane Street Challenge

5 months ago

Advent of Code has long been a favorite December ritual at Jane...

What the interns have wrought, 2025 edition

8 months ago

Yet again, we’re at the end of our internship season, and so...

A Higgs-bugson in the Linux Kernel

10 months ago

We recently ran across a strange higgs-bugson that manifested itself in a...

Introducing OxCaml

11 months ago

At Jane Street, we’ve been actively making improvements to OCaml for a...

Advent of Hardcaml

about 1 year ago

Advent of Code is an annual Advent calendar featuring small programming puzzles...

How we accidentally built a better build system for OCaml

over 1 year ago

A “build system” is one of the most important tools in a...