> I think people go to high-technology finance because they want to test themselves against a harder class of problem in a more adversarial setting against people who feel the same.

Maybe this is so at other finance firms, but my experience with developers who go to Jane Street is quite different. Because Jane Street heavily advertises OCaml as part of its recruiting strategy, I know many people who ended up there just because they wanted to program in OCaml while still getting FAANG comparable salaries. They don't care at all about finance (at least initially, maybe it becomes an acquired taste for some).

Allegedly they use it because it's "readable" by both tech and traders. I don't really buy that; I think the real reason is that one of the founders used it because they liked it, and now they have all this legacy stuff laying around that's too expensive/time consuming/risky to replace. I hear TGS is stuck with their Fortran stack precisely for this reason.

Having worked in HFT for well over a decade now, I'd say OCaml is more of a deterrent than helps in getting access to larger pool of talent.

Esoteric languages is often a good screener for good devs.

A large talent pool isn't necessarily a positive if you don't spend a lot of effort on your recruiting (mostly filtering) process. It really just increases the risk of bad hires.

This. If you want really good devs, they tend to play around with all sorts of things that don't necessarily have economical value. This includes esoteric programming languages.

I'm struggling to understand how OCaml reduces the risk of bad hires and other languages don't.

Languages large swaths of the industry know (Java, C#, JS, Python, etc) include a subset of people who learned it purely for the job opportunities but aren't competent developers. The number of people who learn more niche languages like an ML or Haskell has a far lower % of people of that type.

An example of a language that I could see shifting from one to the other pretty soon is Rust now that it could be a way in to many of the high paying big companies like Google, Amazon, etc.

I agree with this to some extent. However in case of firms like Jane or Citadel or Quadrature you have to have a well documented, long track record of accomplishments in various orgs before your CV lands on their desks.

These companies hire from a different pool than you described.

I don't know if that is true. As a new grad, I got invited to interview for Point72, Headlands Tech, HRT, Two Sigma. (although some of these are in a different "tier", and different business than Jane Street or Citadel).

I definitely didn't have more special accomplishments than 2 typical internships and both were not FAANG.

I should have been more specific in my trite original post. I think at the college hire / intern level, its not quite as useful as everyone is so green .. so people screen based on college / attempts at raw brainpower games with brain teaser puzzles and stuff.

On the more experienced end of the scale, I'm often surprised to see how many resumes with 3-5 years experience are basically Python-only. This, in the absence of something else in the resume that speaks to domain expertise or something.. its definitely a less exciting prospect to me.

The 2000s version of this were Java-only devs and people who acted as though we didn't need to know how the hardware worked anymore because Java abstracted it away. You see this attitude with some cloud/k8s type dev today.

In both situations, naively.. yes you don't need to understand much about the hardware for your basic implementations.

Arguably once you get into moderate levels of complexity you actually have higher cognitive overhead because you need to understand how the underlying hardware behaves and how the abstraction layers between you & it interplay..

I'm going to venture a prediction that knowing how computers really work isn't every going to go completely out of style, or even decrease in utility in absolute terms. It's already decreasing in utility in relative terms as more and more useful stuff becomes possible without it, but someone will always write the thing underneath the thing underneath the thing.

The AGI/singularity conversation aside of course, which I am not at all interested in having. ;)

While this may be true, JS explicitly says they don’t expect you to come in knowing Ocaml. So the filtering hypothesis doesn’t really hold.

That makes sense to me. But, in light of that, the ones who do go to Jane Street are relatively more likely to be interested in their tech stack and OCaml, as opposed to wanting to "test themselves" in the "adversarial setting" that the post I quoted describes. In contrast, the couple of people I know who went to HRT or Jump Street are much more like that description. They deliberately targeted HFT work, whereas Jane Street has more people who "fell into it" because of this outside interest.

I mean, Yaron used to go around a lot and give guest lectures about OCaml programming "in industry" at all sorts of functional programming courses in universities. I have to imagine they thereby recruited people who would have never considered HFT shops otherwise.

Jane Street recruits silly hard from Cornell’s CS dept because part of our required curriculum is functional programming w OCaml. They definitely introduce a lot of math/cs kids to the idea that finance can be a meaningful technical challenge instead of just Dyson bros in spreadsheets.

Then again I think one of the founders or top execs is an alum, so it’s possible Cornell has that course in that language because of Jane Street

There are a lot of universities doing functional programming in either Haskell or OCaml as part of their curriculum right now, so I don't know if that's really the reason.

Boy am I glad I never have to take 3110 again.

A larger talent pool isn't always better.

Every few months or so I run out of patience with C++ and wonder about the alternatives, of which there seem to be very few in HFT. Jane Street stands out for that reason. It's a smaller talent pool but I don't think it's a subset of those that the C++ shops can attract.

Rust is getting pretty popular among low latency firms. Many of my peers (myself included) would definitely show interest in a rust shop. OCaml - not so much.

> OCaml - not so much.

Is that only because OCaml has more of an FP flavor, or is it something else about the language?

> I think people go to high-technology finance because they want to test themselves against a harder class of problem in a more adversarial setting against people who feel the same.

That and among developers, I think Jane Street has hit "mythological status". I've known about Jane Street since I was an undergrad looking for internships and it was always talked about like: "oh yeah, that's where the REALLY smart people go to work". I think a little part of going to work there for everyone is figuratively one-upping your friends from college, you made to the place where geniuses worked.

> But as for "could"? Shit you can do that at Google, Microsoft, Amazon, Meta

Yes, these are some of the highest paying companies on the planet. Your statement is not a put-down of Jane Street.

Oh just to clarify, it was not my intention to put down Jane in the slightest. It's a fascinating firm in a fascinating field that is obviously full of elite mathematicians and technologists. I'd most likely be willing to work there.