Perhaps you and I just have different views about what the pool of programming talent looks like. I think of your average CS sophomore as someone who will most likely struggle with Fizzbuzz in an interview setting. I'd say if they're a college sophomore, they just read Intro to Algorithms for the first time, and they can solve this problem in 10 minutes, that means they have an extraordinary ability to deeply and rapidly master material, and they'll be able to handle whatever challenge you throw at them. (Either that or they started programming way before they started college.)

In my observation the default state of a student reading a textbook is it goes in one ear and out the other. Most students temporarily acquire a superficial understanding of the concepts which allows them to answer test questions and get a decent grade. To see something in the wild and instantly recognize that it's isomorphic to a concept you studied years ago requires a level of mastery/passion well beyond what it takes to get an A. (I'm talking about school in general here, of course the fact that interviews index so heavily on data structures/algorithms ends up distorting things a lot from the baseline. Still, if you solve this problem in 10 minutes you're one helluva sophomore.)

>Also, working at a "hard startup" has nothing to do with "advancing the state of the art in CS".

I think of "hard technology" like rethinkdb as being exactly equivalent to cutting edge stuff that advances the state of the art in some way... again, maybe there's just been a misunderstanding/miscommunication here