> In addition to the obvious time zone constraints, I think payroll taxes and such are a major regulatory boundary that you need to cross in addition to having "all your shit together" as one of the top comments puts it.

This can be annoying even across state boundaries, let alone internationally, for smaller companies that aren't already operating in several states. Consider also things like group health insurance, which are often geographically bound (sometimes even to a single city).

Right?

It boggles the mind that the biggest companies on Earth are the likes of Instagram instead of a huge company called "Adapt" which takes care of all that between employee and employer as a third party.

I have no personal experience but I have been told that even if you farm a lot of things out there is a certain amount of paperwork (and cost) that you have to handle in-house.

Hm, that's a shame. That seems to me to be just accidental, not essential complexity, too.

Well, a lot of it is a patchwork of government rules and regulations. Here's a long post about it from Mitchell at HashiCorp:

https://news.ycombinator.com/item?id=17022563

Right, that's exactly what I find baffling.

Right now, if N companies want to hire in M countries, the total expenditure in HR departments is in the order of O(N*M), when it could (theoretically, ideally) be O(N + M).

Which would then crucify its employees and suck rent out of both sides.

Also there are vast diferences in labor law between countries