I was specificially asking to work on the exchange trading backend, as that's what I was interested in. It was at a time when Coinbase was using javascript for

I was specificially asking to work on the exchange trading backend, as that's what I was interested in. It was at a time when Coinbase was using javascript for the trading engine if I recall correctly (I think they moved to C++ since then, but not sure). When I applied to a quantitative hedge fund, I was being asked questions about synchronizing data structures between threads without using mutexes (again not something you often do in a high level language). I was accepted there, although I couldn't go to work there because of health reasons. At the end I went back to Google where I had to launch a new machine learning model without introducing even 0.1ms latency in the ads backend. Good luck doing that in a high level language.