In the games industry we have a role called “tools programmer” which is a person who works on tooling to accelerate development, sometimes these can be extensions to the editor for a specialisation for a game (say, a tyre builder for a racing game) and sometimes they can be more broad (a distribution tool using libtorrent so that a new build of the game can be shipped worldwide very quickly).
There are people who might refer to you as a backend programmer (if the focus is services and daemons), or platform engineer (if the focus is developer velocity).
Largely it depends what your primary focus is.
I do work on Cloud Infrastructure at times, but honestly it's the smallest part of what I do. It's usually addressed in the architectural designs and I have to touch it incrementally. What I do much more often is writing tools, daemons, and services for distributed systems. I end up calling myself a Distributed Systems Software Engineer to reflect the idea that what I work on is systems and software, and most of them are non-monoliths (from a systems perspective).
Do you have any thoughts on Systems Engineers or the title that I prefer to call myself?