Anecdotal, but as a hiring manager, I've interacted with only one person from Harvard, he was very impressed with himself and knew how to talk but when we asked him to do a small test project (we paid him for), the work he did was really not great. He took a long time to deliver something that barely worked, didn't follow best practices/common idioms of the framework he was using (framework that he selected by himself and supposedly had 2 years of experience in). He was also extremely aggressive in salary negotiations which is fine if you can deliver (and I know people who made a lot of money by being good at salary negotiation) but less so when you can't.
I've worked with quite a few MIT graduates and overall they've all been very good at what they do. So, sample size of one in the case of Harvard but I think Ivy leagues are not all created equal for a given major.
People sometimes get the impression that Ivies are about admitting only the best and brightest. But there are exceptions. Legacy admission, donor influence diversity picks. Also, I say diversity but I don't just mean race based picks. They are trying to build a student body that isn't made of people who all like the same sport for example. They need to fill out the various clubs.
I think the engineering based elite schools like MIT, Caltech or Stanford are probably a safer bet.
I also think being great in the academic world way different from the "real world" and there can be an adjustment period. I know there was for me!
I've worked with quite a few MIT graduates and overall they've all been very good at what they do. So, sample size of one in the case of Harvard but I think Ivy leagues are not all created equal for a given major.