While not a role, I've included it as the substantial years of experience I've had in the language have been a primary reason I have been hired at a number of the roles I have held.
In April of 2015, I watched a talk by Dan Callahan at PyCon2015 entitled "My Python's a little Rust-y". This talk awakened my interest in Rust, and I began learning it the same week, around a month before the language hit its stable 1.0 release.
After taking a few weeks to get over Rust's well known "learning cliff", I was in love with the language and began using it for all academic projects with a free language choice, and used it to develop some internal tooling at Brace IT.
Before encountering Rust, I had never fully settled on a langauge that felt "right" to me. Languages like C and C++ had speed and performance, but lacked the nice APIs I had learned to rely on from Python such as it's iterator adaptors. Languages like Java and PHP felt too bloated and over-engineered. I'd just about settled on "pythons ergonomics, with strong typing, and C performance" as what I wanted out of a language, but had assumed was not technically possible.
Rust proved that assumption incorrect.
I continued using Rust for my personal projects and academic works, including on my final year thesis project.
In September of 2020, I picked up my first role writing rust full time at MotionMetrics. This set the trend for my career moving forward, and you can find the exact specifics of what Rust was used for in each of my roles on their respective pages.
I have also developed a 6 week course (one hour a week), which aims to get a team of competent programmers from a passing knowledge of rusts existence, to writing production ready code. I may make this course available publicly at some point, but to date I have used it to successfuly train the rest of the engineers at Element Human, and plan to do the same at SteamaCo.