You're missing one of my favorites, "Involving undergraduates in research." Especially for top students, I feel this element is key (I'm biased). Even for unde

You're missing one of my favorites, "Involving undergraduates in research." Especially for top students, I feel this element is key (I'm biased). Even for undergrads with no desire to go on to do academic work, it's a good experience to work on a well-defined but hard problem that fundamentally might have either no solution or where the answer is "that doesn't work." It provides undergrads with confidence when they go on to their next job because, frankly, most students will never encounter anything as mentally challenging or technically risky in the rest of their career, entering it with a BA/BS. Not saying that as a bad thing. Companies (startup or established) have plenty of other risks and challenges (social, business, process, quality, integration, dependencies, schedule, etc.), but the pure technical "is this even possible?" ones are the sort of thing you don't sort out mid-flight with a full or even partial team staffed up --- though you might have some PhDs (Google model) or 15+year veterans of the area (MSFT model) working alone to figure that out before you ramp up a full project.