Fly.io

In Plain Language

The core of Fly.io is "running containers close to your users." Think of a container as "your whole app environment, packaged up" — Fly.io copies it onto machines around the world and runs it.

It differs from Serverless: your program can stay running, which makes it especially good for WebSockets, live chat, and other services needing long-lived connections. The trade-off is you manage a bit more around resources and consistency, and the entry bar is higher than Cloudflare.

Architecture

How It Flows

When You Actually Need Fly

Reach for Fly when the job has a specific shape:

• Long-lived connections — websockets, multiplayer game servers, live collaboration, anything where the client and server stay talking instead of trading one-off requests.
• Compute near users in many regions — when latency matters worldwide and you want your code running physically close to people, not in a single distant data center.

For a static site or a plain request-and-response API, that power is more than you need, and a simpler platform will get you there with less to manage.

Key Takeaways

• Fly.io = deploy containers to multiple regions worldwide.
• Supports long-lived connections — good for real-time, always-on backends.
• High flexibility, but you tend to resources and data consistency yourself.