So far.

The two important things here are:

1. Fly.io makes it really easy to write through a single primary application instance

2. There are ways to solve this problem so your application doesn't have to worry about it.

Right now, you have to be a little careful bouncing app instances. If you bounce the writer, you can't perform writes for 15s or whatever. This is a big problem during deploys.

There are a tremendous number of Fly.io users that are fine with this limitation, though. It's pretty valuable for some segment of our customers right now.