I am hesitant to try a framework written by people who clearly spent more time on a verbose blog post then actually working on their product. Clearly they didn't test their sites on any size viewport beyond standard desktop displays :p
I interviewed at both. The larger companies were more likely to give me 'programming challenges' or puzzles (usually small mockups) for me to do ahead of times while startups tended to be more conversational and, quite frankly, didn't ask as hard of questions.
I am honestly a little shocked by this. I am a university student and this past semester I interviewed with around 10 companies in the Bay area, all of which were for Front-End engineering positions. I can only think of one company which did not give me any 'front end specific' questions. I was asked everything from hoisting and closures to explaining how Webkit works and various ways to improve page load time. Are you free to elaborate on what companies you spoke with?