I've spent the last year working as an annotator/evaluator for DataAnnotation. All the frontier/flagship model providers use independent contractors for iterating on their LLMs. I'm not able to tell you which models I've worked on as a term of my NDA.

The system prompt seems plausible, but in my experience they are much much much much longer and more verbose.

What layer do those typically work at and how ? And how did you get into the field ?

you can just look at the traffic in mitmproxy.