Career paths for quants are both diverse and random.
A bundle of paths are what I call project management, a mix of finding out what needs to be done, getting people to do it and adjusting the result to be useful. That's a mix of people management, IT, business analysis and general politicking.
Some, a few, become ever more senior quants. One characteristic I've seen in the top level of Quants is the ability to win arguments but at the same time not cause the other person to lose face or get upset, plus of course the maths and finance stuff.
Some join consultancies where a mix of finance and maths is useful.