Non technical Fly.io founder here: LiveView and Elixir work very well distributed all over the world. Here's an example app I fumbled my way through to show it in action: https://liveview-counter.fly.dev/
We intentionally give you super user access to your DBs so it's easy to migrate or spin up your own replicas. Our bet is that _most_ people won't outgrow our Postgres but having an escape hatch is still very comforting.
We previously worked on Compose.com. We, at least, understand how to manage huge databases when the time comes.