Nexos vs Fly.io: branch previews without the ops

Fly.io is a beautiful platform if you want production-grade VMs deployed globally with low-level control over networking and regions. You write a fly.toml, you deploy a Machine, you tune it to the millimetre.

That power is exactly the opposite of what you want for preview environments. When a reviewer needs a URL to click through a pull request, nobody wants to think about regions, machine sizes, or volumes. They want the URL.

What Fly is great at

• Low-latency production services deployed close to users
• Full control over VM size, regions, and networking
• Persistent volumes and their own Postgres primitive
• A strong story for long-running processes and WebSocket-heavy apps

Where it becomes friction for previews

On Fly, every branch-preview setup is something you script. You add a GitHub Action. You configure volume lifecycles. You remember to destroy Machines when the PR closes or you pay for idle capacity. For a team that ships fast, that tooling work is real overhead.

Nexos: zero-ops previews

Nexos is opinionated where Fly is flexible. You do not pick a region. You do not size a Machine. You push a branch and a full-stack environment shows up. When the branch is deleted, it is torn down automatically. When the environment is paused, billing stops.

Under the hood, the platform does all the scheduling, the resource allocation, the container orchestration, and the URL provisioning. You see a URL and a log stream.

The complementary stack

A common pattern: production services on Fly for their global low-latency properties; preview environments on Nexos so every pull request has its own working copy of the stack. Your developers get fast feedback, your ops team keeps the tight control they want in production.