Facebook doesn't just do web development and analytics.
Their datacenters alone are big enough to warrant hardware engineers for their custom servers and switches, facilities designers, ex-HVAC employees, et cetera. (http://www.opencompute.org/)
This is obviously a serious acquisition, and Carmack's talent no doubt played a small part in it.
Explain again why "employee" in the title makes this clickbait?
Because it makes it seem like he's just another peon, rather than the CTO of a subsidiary. I know that Facebook requires a very diverse set of skils/positions in order to run, it just seems kind of hilarious to say John Carmack is now a Facebook employee :)
