I'm curious, have you heard of any of these: Data Engineer, Machine Learning Engineer (MLE), Staff Software Engineer.

I'm surprised you've never come across the term SRE/Production Engineer before (Assuming you meant to say "have only __just__ heard about what an SRE is"). I live in New Zealand and I'm pretty sure I knew what an SRE was before I even joined a big tech company (Not a SV one btw).