I'm not sure how feasible that would have been three years ago.

An Agent Team of Opus 4.6 should be able to reverse engineer the simulator in a day or two, instead of 3 years. But it wouldnt be so much fun I guess.

Good luck doing that without proper tests - I assume finance stuff is quite complicated and blanked porting with AI is insanely difficult, especially companies have failed in porting it by hand.