I've been telling people for 25 years that Jane Street is not interested in formal methods. No more! And we're actively hiring to form a new formal methods team! blog.janestreet.com/formal-metho...

Formal methods and the future of programming

I’ve been telling people for the last 25 years that Jane Street as an organization was just not interested in formal methods.

blog.janestreet.com

This is a fairly wild post about OxCaml Labs from @avsm . It's hard to summarize the stuff they're doing, but, some examples: - Some wild vibecoding - A formal semantics for package managers - A decade of docker containers (including OxCaml!?!) anil.recoil.org/projects/oxc...

OxCaml Labs

OxCaml Labs

anil.recoil.org

Another fun hiring spot at Jane Street: we're looking to hire some great hybrid writers-and-engineers. As we grow and do more, communication becomes ever more important, for both internal and external audiences. www.janestreet.com/join-jane-st...

It's been a minute, but, time for another Signals and Threads, this one with Will Wilson about the testing tools he's building at @antithesis.com. And, in a bow to modernity, we have a video version of this one too! youtu.be/F_LvzcdNH3Q?...

Why Testing Is Hard and How to Fix It

YouTube video by Jane Street

youtu.be

A poor craftsman blames his tools. Wealthy craftsmen also blame their tools. Lots of tool-blaming going around.

I wonder if we're starting to hit a deflationary era in software engineering. For the first time, we're starting to talk about this in a planning context; it can make sense to put off some projects because we expect they'll be easier to achieve in the future than today.

Seems like a good time as any to say I'm: (1) moving to New York next week, where I'll: (2) be writing OxCaml at Jane Street! Excited to start the next thing :)

Joe Cutler@alphaconvert.bsky.social · 6mo ago

Successfully defended my dissertation today. Now Dr. Joe!

February 10th, and thus the inaugural edition of NINeS is just around the corner. You can participate from anywhere in the world, at times that are convenient to you. See https://nines-conference.org/attend for information on how you can participate. We hope to see you on Feb 10th!

My regular PSA that if you enjoy working on developer tools, then Jane Street is kind of an amazing place. Apply here! There's no special posting, so just apply for the Software Engineering role, and express your interests in dev-tools in a note. janestreet.com/apply

We've had an exciting couple of weeks full of opportunities to teach people about the exciting (and mildly bewildering) features of OxCaml. And...we're looking to hire an experienced educator to help us in this work. Please share this with anyone you think might be a good fit!

I did anothr version of my "Saga of Mulicore OCaml" talk, but this time, nerve-wrackingly, the authors of the original paper were all there! Here's the link to the talk, which is found towards the end of the recording for the whole session. t.co/FQTmsFWji0

Me too! (But Max knows more about it than I do.)

Max Slater@thenumb.at · 10mo ago

I'll be at ICFP/SPLASH if anyone wants to chat about OxCaml!

Most companies be like “We daren’t go functional, we might not be able to hire”. Jane Street be like “Hold. Our. Beer.”

Yaron Minsky@yminsky.bsky.social · 10mo ago

Excited to say that we're looking to hire someone to focus on OxCaml education! We're doing enough to change the language that we have a pretty big internal education task ahead of us, and we want to hire someone to focus on it! Please share this with others! www.janestreet.com/join-jane-st...

Excited to say that we're looking to hire someone to focus on OxCaml education! We're doing enough to change the language that we have a pretty big internal education task ahead of us, and we want to hire someone to focus on it! Please share this with others! www.janestreet.com/join-jane-st...

OxCaml Educator :: Jane Street

Jane Street is a quantitative trading firm and liquidity provider with a unique focus on technology and collaborative problem solving.

janestreet.com

A fun talk about...hacking OCaml. Basically, what you get when you supercollide a systems-y OCaml developer and a CTF. www.youtube.com/watch?v=SV9V...

Hacking OCaml

YouTube video by Jane Street

youtube.com

On Advisory Opinions, Sarah Isgur and David French speak with me about enumerated powers. The segment begins 43-44 minutes in, depending on format. This was a good conversation among people with different approaches to constitutional interpretation. thedispatch.com/podcast/advi...

The Oldest Constitutional Question | Interview: Richard Primus

Originalism through the lens of sola scriptura.

thedispatch.com

They should know the difference between TeX and LaTeX, so they could hate Lamport less and Knuth more.

Clearly, the reason for the AI work is to build an AI capable of porting from Latex to Typst.

a ton of crates@tonofcrates.bsky.social · 11mo ago

"we need a manhattan project for AI" no what we really need is a manhattan project for porting every math TeX package to Typst (and please start with mathpartir)

"we need a manhattan project for AI" no what we really need is a manhattan project for porting every math TeX package to Typst (and please start with mathpartir)

I've raised my kids well, I think.

A new episode of Signals and Threads just dropped! This one is an interview with Chris Lattner talking about Mojo, a new-ish language for GPU programming that's aiming to be an alternative to the CUDA stack. signalsandthreads.com/why-ml-needs...

Signals and Threads Podcast

Listen in on Jane Street’s Ron Minsky as he has conversations with engineers working on everything from clock synchronization to reliable multicast, build systems to reconfigurable hardware. Get a pee...

signalsandthreads.com

This was a great talk from Will Crichton. I think Will's approach to approaching questions around language tooling and teaching is compelling, though I wonder how far the approach can scale! youtu.be/R0dP-QR5wQo?...

I just finished our yearly roundup of this year's intern projects, and it was a real bumper crop! Lots of fun projects, and some cameos from OxCaml... blog.janestreet.com/wrought-2025/

What the interns have wrought, 2025 edition

Yet again, we’re at the end of our internship season, and so it’s time to summarize whatthe interns were up to!

blog.janestreet.com

Just ran across this old post from a former intern about Jane Street's approach to programming and code review. I thought it was a pretty accurate, and I think captures something important about how OCaml's design makes code review easier and more effective. digitalfreepen.com/2017/01/07/j...

This will remove so many unnecessary OCaml functors from our codebases. My rough rule of thumb is that if a functor is not applied more than once in a codebase, it doesn’t need to be a functor. Parameterised libraries lets us easily do one-shot reuse of existing modules in a different context.

Yaron Minsky@yminsky.bsky.social · last yr.

We've finally landed a full version internally (coming to an OxCaml near you soon!) of a new feature called parameterized libraries. It's basically an answer to a problem I first ran into 23 years ago. Here's a thread about it on the caml-list. inbox.vuxu.org/caml-list/10...

We've finally landed a full version internally (coming to an OxCaml near you soon!) of a new feature called parameterized libraries. It's basically an answer to a problem I first ran into 23 years ago. Here's a thread about it on the caml-list. inbox.vuxu.org/caml-list/10...

A new epsiode of Signals and Threads has just dropped: "The Thermodynamics of Trading". I got to talk to Dan Pontecorvo from our physical engineering team about the complex work that goes into our physical spaces to make the work we do at Jane Street possible. signalsandthreads.com/the-thermody...

Signals and Threads Podcast

Listen in on Jane Street’s Ron Minsky as he has conversations with engineers working on everything from clock synchronization to reliable multicast, build systems to reconfigurable hardware. Get a pee...

signalsandthreads.com

I had a lot of fun giving this talk in Singapore about the many-years-long saga of multicore OCaml, and in particular, the work over the least 2.5 years of getting it ready for production work within Jane Street's walls. www.youtube.com/watch?v=XGGS...

The Saga of Multicore OCaml

YouTube video by Jane Street

youtube.com

My approach so far is to treat AI code assistants as an extension of “a large team with communication challenges working on the same codebase.” You need better tools to clean up the local optima that individual agents get stuck in. See prune and merlint: discuss.ocaml.org/t/ann-new-to...

Yet another small OCaml/OxCaml diff has been squished! Polymorphic parameters has just gotten merged upstream: github.com/ocaml/ocaml/... There's more to go (include functor, for example: github.com/ocaml/RFCs/p...), but it's nice to see more progress in this space.

Polymorphic Parameters by voodoos · Pull Request #13806 · ocaml/ocaml

This upstreaming PR adds the possibility to have function parameters with polymorphic types in the language. This work was originally done by @lpw25 in Jane Street's fork of the compiler with e...

github.com