The Silicon Valley companies massively over hired.
Using twitter as an example, they used to publicly disclose every site and their entire tech stack.
I have to write proposals and estimates and when Elon decided to axe half the company of 8000 I was curious..
I assigned the biggest functional team I could (e.g. just create units of 10 and plan for 2 teams to compete on everything). I assumed a full 20 person IT department at every site, etc.. Then I added 20% to my total and then 20% again for management.
I came up with an organisation of ~1200, Twitter was at 8000.
I had excluded content moderators and ad sellers because I had no experience in estimating that but it gives a idea of the problem.
I think the idea was to deny competition people but in reality that kind of staff bloat will hurt the big companies
Firstly it was just a bit of fun but from memory...
Twitter was listed as having 2 data centers and a couple dozen satellite offices.
I forgot the data center estimate, but most of those satelites were tiny. Google gave me the floor area for a couple and they were for 20-60 people (assuming a desk consumes 6m2 and dividing the office area by that).
Assuming an IT department of 20 for such an office is rediculous but I was trying to overestimate.