That's a pretty strong generalization to present without evidence. I'm sure some companies favor candidates from certain schools, but I've never seen any evide

That's a pretty strong generalization to present without evidence. I'm sure some companies favor candidates from certain schools, but I've never seen any evidence that it's a systemic problem. The one exception I can think of is high level, publicly facing positions. I could see a company choosing a CTO with a PhD from MIT over one with a PhD from somewhere else, just to impress investors, for example. For rank and file software engineer positions, alma mater isn't usually so important. As far as STEM goes, those fields require so much math and other background knowledge that it's almost unbelievable that somebody could learn it all on their own. Not that it's impossible, but it's a pretty wild claim, and it's reasonable that people would be suspicious.