Well the interview bars among FAANG aren't consistent with each other either. I would say Jane Street interviews are on par or perhaps easier compared to Google and Facebook, but it likely depends on your personal proficiencies.
Interestingly enough Jane Street has a fairly negative reputation within certain engineering schools that they love to recruit from. Hard to hire talented and passionate people if the only thing you can offer is a bit more money at the expense of everything else people look for in a job.
This isn't really accurate of Jane Street. As the other commenter mentioned, it's not a hedge fund. Secondly, engineering culture at JS is typically the opposite of what you described. A lot of time is spent to make sure all code written is quality, things move slower than a company like Facebook for sure.
> Best in class engineering and internet scale problems? Nope
This is mostly true apart from a few specific teams and projects. I think most passionate engineers would find the work uninspiring.
Jane Street has spent a lot of resources into making sure they're well known as one of the "top employers". Their recruiters put a lot of effort into pseudo-anonymously promoting the company on websites like reddit and blind. It's pretty forward thinking actually as younger tech savvy candidates no longer pay attention to sites like glassdoor and seek information through these discussion forums. The natural evolution of fake glassdoor reviews is astroturfing I guess.
Firm performance is excellent but IMHO the only reason to work there as an engineer is for marginally more money.
As someone who has interviewed thrice and passed once, I disagree. Jane Street is extremely good at marketing themselves; before I ever worked there I received over $500 worth of "swag" (including a free iPad) just for attending talks and hiring events. The official recruiting strategy is grassroots where recruiters have anonymous reddit/hn/blind accounts to praise the company semi-anonymously. So you have a bunch of accounts posing as real employees or students talking up the company and the prestige of working there.
They sell exclusivity and mystery, but they definitely pay top of market salaries. I don't personally believe the actual interviews are any harder than top FAANG companies but they did seem to recruit exclusively from FAANG and/or top engineering schools.