This is excellent, but I'm not following how the multi-region deployments work. Is Anycast involved in this somehow?

Maybe a comparison to AWS Global Accelerator would be helpful to understand the "global" aspect. Having instances in multiple regions is just a starting point.

Ahhh got it, this is focusing primarily on load balancing at a lower layer of routing then than what I'm referring to. While not wrong, "global load balancing" threw me off a bit.

EDIT: see the other reply, appears that it handles both given it leverages Fly's Anycast setup.

We're hosted on HN darling, Fly.io. Multi region instances come with a anycast IP

Oh interesting, good to know.