The servers
In short
A project runs on up to four servers — Design, Build, Rehearsal and Live — each created when the project reaches the stage it serves. The Design Server is free and serves your mocked preview; the other three are real infrastructure, monitored and backed up, and drawing from the wallet while they exist.
A project’s infrastructure is named after the stage it serves. Servers are created as the project reaches each stage, so a project early in its life has only the first of them — that is normal rather than a setup step you missed.
| Server | Serves | What runs on it |
|---|---|---|
| Design Server | Design | Your screens on mocked data, for you |
| Build Server | Build | The app with a real backend, for you |
| Rehearsal Server | Rehearsal | The dress rehearsal on real infrastructure |
| Live Server | Live | Production — real users, real data |
The Design Server is the odd one out: there is no machine reserved for you in Design. It is the platform building and serving your preview, shown as a server so the dashboard can tell you at a glance whether your design preview is up. It costs nothing to keep, holds no data, and is never monitored or backed up.
It is also the one server that goes away. Once the project moves on to Build, the real app on the Build Server replaces the mocked preview, and the Design Server is shown as retired on the dashboard — shut down for good rather than waiting to be restarted. The other three stay for the life of the project.
What is deployed on one
A server holds a release: a specific version of the project, deployed at a specific time. Promoting between stages is how a release moves up the ladder — see promoting between stages. Two servers can hold different versions, and usually do: Rehearsal runs ahead of Live by design.
Health
Rehearsal and Live are monitored, and problems are recorded as incidents against the environment they happened in. An incident stays open until it is resolved, so “healthy” means nothing is currently open rather than nothing has ever gone wrong.
Severity matters: something being down is an outage, an error is a fault that has not taken the app down, and a warning is worth reading but not worth waking up for.
Backups
Backups run on a schedule for the servers that hold real data, and each one either completed or it did not — a backup that failed silently is worse than none. Restores are drilled deliberately in Rehearsal, while nothing depends on them, rather than attempted for the first time during an incident.
What they cost
A real server — Build, Rehearsal, Live — draws from the wallet for as long as it exists, whether or not anyone is using it. That is the argument for tearing down an environment when a project is paused — and the reason Design, whose server is not real infrastructure, costs only the agent work you ask for.