I don't understand what I'm looking at. Who is tagging companies? Why would leetcode know the specific questions people are being asked to whiteboard?

People who interview at these companies report on their interview experience. It's true, these leetcode style questions do get asked and not just by the FAANG companies but lots of much smaller, no-name companies as well.

Yes, you can certainly find companies out there that don't interview in this way, but leetcode interviews are extremely common.

Strange. Not something I've seen, but I'm also very picky about the companies that I have applied to in the past–to the point of picking specific people I want to work with–and never ever go after mega orgs (I've contracted with some of them, and that's enough to know to stay away). Seems like a practice that would actually bias in favor of more junior developers, because of the emphasis on speed and familiarity to CS classwork. Obviously some programming jobs are heavy on algorithms, but that's neither the case for most roles nor what typically sets apart senior developers from juniors.