I've worked on several such teams (not at FANGy places, but some household names), variously called just the NOC or SOC (early on in my career, the role was als

I've worked on several such teams (not at FANGy places, but some household names), variously called just the NOC or SOC (early on in my career, the role was also a kind of on-duty Linux admin/computer generalist), Command Center, and Mission Control. It was great fun a lot of the time but the hours got to be tiresome. I would be very surprised if any enterprise of significant size and IT complexity didn't have an IT incident response team. I'm biased but I think they are a necessity in complex environments where oncall engineers can't possibly even keep track of all their integrators and integrators' integrators, etc. It also helps to have incident commanders who do that job multiple times a week instead of a few times a decade.