I suggest reading the book "Clean Code". I've worked with traders/business analysts who do some coding but it isn't their full time job and their code quality

I suggest reading the book "Clean Code". I've worked with traders/business analysts who do some coding but it isn't their full time job and their code quality isn't great. After having them read the book and then following up with code reviews from a senior developer they improved their code significantly in just a few months. "Refactoring" is also a good book, but a lot of time it is too advanced for people who copy and paste code all over and don't use functions, etc.