This is probably unfair, but I think that most of them are going to lack the math background to advance their skills very far from implementing simple CRUD apps in common frameworks.
I don't know that STEM people are going to code schools; I think they probably just google the manual, read a few tutorials and have at it.
The math can be learnt, just like coding can be learnt. The only difference between someone with STEM background who codes and someone without, is the order they choose to learn it in.
mgridley is right in that the vast majority of business applications require almost no math, and those that do are usually so specialized that an advisor figures out those equations first as they require a specialized domain knowledge.
Want to build tools that developers build upon? You may need the math, but you can usually already find the algorithms in research papers.
The only exception to this rule (that I can think of) are very specialized niches of development, which ultimately become commoditized and consumed by developers without the math anyways.
Scalability requires mathematical reasoning. From implementing 'you may also like' in an ecommerce store to pulling up a combined list of your friend's pets, I'm reminded over and over again of the gulf between non-mathematical programmers and ones with a basic undergrad math education.
edit: ...along with spending months doing homework on algorithms and big/little-* notation, and learning automata theory, of course. I don't mean to oversimplify.
I don't know that STEM people are going to code schools; I think they probably just google the manual, read a few tutorials and have at it.