Same here!
I am now actually working in compilers, which is one thing I'm really passionate about, but not something I was doing professionaly. I managed to turn a toy project and some blog posts into an actual job at almost 40, so, thank you HN!
I work at ServiceNow, which sells an enterprise platform and a ton of products built on top of it.
Internal teams and customers can extend the platform by writing JavaScript, hence we have a JS runtime in the platform (the venerable https://github.com/mozilla/rhino/), which our team works on.