Lots of engineers write, too. My favorite example of "very different day job" is Gene Wolfe, who worked as an industrial engineer (he famously worked on the original machine that produced Pringles potato chips), and spent most of his working life as an editor of the magazine Plant Engineering. R. A. Lafferty worked as a full-time electrical engineer for Clark Electrical Supply Company all his life, though he eventual…
I’m one of those, although I tend to de-emphasize this fact in most of my social interactions (not just writing related) since people tend to react weirdly to learning that I program computers for a living. Instead, the bio for my writings says, “[he] spends his days as an insignificant cog in the machinery of corporate America.”
I’ve had modest success with a few dozen stories and poems published over the last dozen years, but I don’t expect it will ever be a major source of income for me.