I will reply for the quantitative developer role, given your description I suppose that it's what you are looking for.

Succinctly, I would say that it's a strong computer scientist/developer highly interested in finance to be able to understand/discuss/implement business requests.

It's important to be able to work under pressure (when there is a problem on an automaton for instance, etc.). It's also important to be able to frequently switch between tasks.

I would not say that you have to be extra smart.

I started as a computer scientist in a bank, turned quantitative developer and then trader a couple of years later.