Again: it's the premise of the platform. If you're saying "you picked a hard problem to work on", I guess I agree.
We cannot in fact assign our customers apps to 0.3% of our proxies! When you deploy an app in Chicago on Fly.io, it has to work from a Sydney edge. I mean, that's part of the DX; there are deeper reasons why it would have to work that way (due to BGP4), but we don't even get there before becoming a different platform.
I think the impedance mismatch here is I am assuming we are talking about a hyperscaler cloud where it would be reasonable to have say 1024 proxies per region. Each app would be assigned to 4/1024 proxies in each region.
I have no idea how big of a compute footprint fly.io is, and maybe due to that the design I am suggesting makes no sense for you.
The design you are suggesting makes no sense for us. That's OK! It's an interesting conversation. But no, you can't fix the problem we're trying to solve with shuffle shard.
We cannot in fact assign our customers apps to 0.3% of our proxies! When you deploy an app in Chicago on Fly.io, it has to work from a Sydney edge. I mean, that's part of the DX; there are deeper reasons why it would have to work that way (due to BGP4), but we don't even get there before becoming a different platform.