[Spooky23]

As an intern at a social services department circa 1997, I wrote some COBOL code that improved the way that a certain calculation was made and eliminated a bunch of processes. (It was calculated with about 20 steps due to people just pasting random crap on top of random crap over 25 years)

I ran into my old boss, who was a family friend, and he told the story that they used that as an example to improve other stuff, and that had saved a few million bucks over the years (iirc they paid for CPU cycles). It was still running as of 2020!