In the early 2000s, Z3 caught many bugs and saved Microsoft hundreds of millions of dollars.

“Z3 was quite powerful. It caught lots of bugs and saved Microsoft hundreds of millions of dollars in the early 2000s. Leo, though, following the great success of Z3, not just for Microsoft, but, like, he and his collaborator entered it into these automated theorem prover comp- competitions where all the ATPs from all over the world come together, and they're given a bunch of problems and a set amount of time, and whichever ATP can kind of correctly prove true or false for those problems, uh, most accurately wins.”