"DevOps" used to be a methodology where a Dev and an Ops share a same goal of delivering value into production, at least, that's in the book I have read. A sort of extension of the Lean System where workers from different areas share a common goal of delivering value to the final customer (in production), the same card may require a backend dev, frontend dev, and an ops to share the goal to take this card from idea t…
This is pretty much how I sum up what you'd have to be to be "a devops engineer": an actually-full-stack developer with a strong facility for communication and for process.
Such folks are hard to find. I only know a few, out of the dozens of folks I've worked with.