Waterloo is really great at making it easy to hire co-ops. This is a huge part of its success. I've heard hiring managers say they prefer UW students over other schools simply because the co-op process at UW is so easy for them.
I remember working with some Waterloo alumni from the 80s/90s and they spoke of the chaos of the application and ranking process when everything was done on paper. I personally can't even fanthom how UW managed to do any of this (although obviously there were less than half the number of students then to what we have today).