Apart from the personal satisfaction of being a mathematician you go straight to the top of my interview list. Anyone with the dedication and commitment to do a maths degree on their own is the sort of person I want to talk to
My (admittedly personal and biased) guide is maths/physics and pref. advanced degrees first.
Followed by CS degrees from really top notch schools and then I ask why, if they are so smart they didn't do maths/physics at MIT? Acceptable answer is a complete overarching love of computer science.
Followed by no formal qualification devs - with some evidence that they have read/learned more than simply the SDK they were using.
And last on the list are CS grads from some no-name, anyone can get in, CS school. People who did a CS degree because their school counselor said it would get them a well paid job.