I did have one whiteboard session on my onsite, but it was about high level web architecture, no code, no algorithms. None of the sessions were specifically about classic algorithms, although there was an "algorithm" session that was about writing some fairly realistic asynchronous code (which for web is something I myself consider required knowledge).

Since I've started participating in the hiring process myself, I'm not aware of people doing whiteboarding (AFAIK it's strongly discouraged because it leaves no digital record), and only the bar raiser session might ask something algorithmic-ish at their discretion (but most do coding exercises to gauge meta stuff like communication skills or methodical approach rather than things like algorithmic complexity).

Training material for tech hiring discourages looking for rote memorization of specifics and instead recommends looking for signals via an open ended exercise.