I've been finding the recently coined term "AI engineer" useful, as a role that's different from machine learning engineering and AI research.

AI engineers build things on top of AI models such as LLMs. They don't train new models, and they don't need a PhD.

It's still a discipline with a surprising amount of depth to it. Knowing how best to apply LLMs isn't nearly as straight forward as some people assume.

I wrote a bit about what AI engineer means here: https://simonwillison.net/2023/Oct/17/open-questions/