The term "design system" made a great career in a very short time. It wasn't really coined until 2016.
Nope, I've worked with and on design systems since 2010. And Brad Frost's Atomic Design [0], a formal system for developing a design system, was first written in 2013. 0 - https://bradfrost.com/blog/post/atomic-web-design/
I you used that term in 2010, you are a real pioneer.
[1] https://twitter.com/search?q=(%23designsystem)%20until%3A201...