They only have one per year. Also, their scheduling system (on paper, rank 1-4 dates) probably means that they send our everything out at once. Previous years: 11/6/17 and 11/15/2018

how many people does UPMC usually interview? << my guess is around 100 (25 per interview day) >> that seems like a lot..

why? what's your guess then << I think ~10 per interview day is more likely