IANAL but i’m pretty sure that even without an NDA anything you develop on the job is considered IP of the company. However, as long as it’s not a blatant copy paste(a rewrite), it’s hard to legally enforce that because they have to prove damages. Meaning that if they shelfed the idea/program, even if it’s a blatant copy paste they can’t do anything.
I have been a network engineer with no degree for many years, but I did have a lot of certs. It’d be nice if there were something similar for programming. But I’ve never seen anyone care that much about the engineer title. I’ve always thought it’s someone who understands his craft/engine design in and out, but doesn’t design it himself. The architect designs it. The tech can perform documented solutions