The end of this article raises the issue of whether Fly.io’s USP, deploying app servers close to your users, is useful for run of the mill web apps. And as much as I like Fly.io and the people associated with it, I’ve wondered this myself. It just seems like serving to US customers from any major US data center is generally fast enough. And I think this might even be true for the world of HTML-over-the-wire web stuff, which Fly.io seems to investing heavily in.
No doubts there are plenty of more niche uses (if I were serving users internationally, I’d probably use Fly.io), but the use case just doesn’t seem as broad as the Heroku/PaaS comparisons make it out to be.
Not only that, having one location for a world-wide user base is usually enough. You can optimize much more through rendering speed, blocking requests etc than by being closer to your user.
And even if your page becomes really popular, 3 locations (Europe, US, East Asia) are enough to be <200ms to any user in the world. And it keeps your setup and cost much lower.
No doubts there are plenty of more niche uses (if I were serving users internationally, I’d probably use Fly.io), but the use case just doesn’t seem as broad as the Heroku/PaaS comparisons make it out to be.