Jane Street might be the only place I've applied to cold in my life - I solved one of the puzzles on their site (I'm not sure how important that ended up being)

Jane Street might be the only place I've applied to cold in my life - I solved one of the puzzles on their site (I'm not sure how important that ended up being) and to my surprise they offered me an interview. The technical interview was a decent bit harder than Google -- we got deeper into implementation instead of just toy problems. I remember filling the white-board walls of the room with code for a garbage collector. Even though the interviews ostensibly didn't require OCaml, knowing a (tiny, tiny) bit about OCaml garbage collection helped. Every interview was with two employees, which I hadn't seen elsewhere. I got the offer, but ended up going elsewhere. In part, I was disappointed to find out that there was VBA involved in the role -- it was their taste in languages that appealed to me and VBA was at the opposite end of the spectrum from OCaml! Weirdly, when I (politely) declined the offer, I never heard another peep from the company, even an acknowledgement or a "good luck". They just ghosted me. Not that they owed me a reply, it just stuck out as the process was very high-touch until that point.