I keep hearing salaries mentioned like this and I'm sure some developers make this but I really don't think the average developer is making this at these companies, based on salary comparison websites, etc. A developer who makes this, I'm assuming, would be working in machine learning / quasi-AI type of stuff and that is probably not the type of job you're going to get right out of college unless you have a PHD. I can't imagine any reason Facebook would pay this to devs for run of the mill dev roles when it's clearly so far above market rate.

Why data structures?

To get through the interview process. Their interviews are a bunch of algorithm questions, and data structures is the starting point.

When he says "data structures" he actually means "interview questions".

Data structures and algorithms interview questions are the only thing that Google and FB care about.

I can imagine an UI designer coming in for an interview. ...yeah I want you to invert a binary tree.

You joke about that, but I had a friend who interviewed for a developer Evangelist role at Google, and literally the only stuff that they were asked was algorithms questions.

Yeah, it was a 50% technical role, but Google didn't care about the OTHER 50% of the job at all...

you'll need them for the interview :P