That said I have no idea. When I worked (many many many many years ago) in a small DC that is perhaps the size of a 2bed apartment we had 4 guys scurrying about doing stuff (hands-on-keyboard, routing cables, replacing hardware etc). This was way before Docker & Kubernetes et al - physical iron and all that. I would assume that in modern DC ops you could run a football field sized DC with less than 10 people due to automation. But that said if part of the actual infrastructure like power or cooling fails, you need to have the right skill-set in place. If the cooler's failed and couldn't just be turned off and on again, we would have been out of luck in my old DC days and would need to call someone in and just hope the servers didn't fry in the meantime. Sounds like a similar deal here.
I don’t think AWS is blowing up a vendors phone when something goes wrong in one of their facilities.
[1] https://www.datacenterknowledge.com/archives/2017/04/07/how-...
All the same gear is still there, its control functions are just ceded to Amazon panels. And integrated to the point of even removing some PLC like devices.
Larger DCs can and do have more staff on-site 24/7 and typically the amount of staff on-site at any given time is driven by SLAs.
I expect the DC in TFA to return to lower staff levels once they've worked on reducing their total "time to restart chiller" or reduced the amount of manual work involved in doing so.
A datacenter with tight SLAs probably needs one 24/7 tech and one 24/7 security guard. That's acheivable with 5 jobs for each, so 10 jobs total. Maybe a couple more techs if the ticket volume is high. Never going to be hundreds of permanent jobs.
Bear in mind that outside of the US and maybe one or two other locations ex-US, almost all of the magic cloud operates out of third-party datacentres, not their own.
They will have a small office on-site where 3–5 people sit, and those people are exclusively dedicated to the cloud equipment itself. The datacentre ops side is, by definition, handled by the third-party datacentre operator.
The guys onsite are clearly only there for "intelligent hands" purposes, as everything else will be done remotely from silicon valley or wherever.
Across all the datacenters the number of operations personnel likely exceeds 100. Think of the unit of scale as a datacenter, with an availability zone potentially containing 10+ of those.
[1] https://www.datacenterfrontier.com/cloud/article/11427911/aw...
They go on site to geographically adjacent DCs and outside that just travel onsite for special projects.