> ## Documentation Index
> Fetch the complete documentation index at: https://docs.vertracloud.app/llms.txt
> Use this file to discover all available pages before exploring further.

# Move an Existing Application to Vertra Cloud

> A checklist for moving an app, its variables, its database and its domain to Vertra Cloud while the old host keeps serving traffic.

Moving doesn't require rewriting the application. The safe order is: bring up a copy, move the
configuration and data, test, and only then move the traffic.

## Check the code

<Check>The port comes from `PORT` and the server listens on `0.0.0.0`.</Check>
<Check>Secrets are read from environment variables, not from the code.</Check>
<Check>The start command doesn't depend on a `Procfile` or a host-specific file.</Check>
<Check>Nothing writes important data only to local disk that another host was backing up for you.</Check>

A `Procfile` like `web: node server.js` becomes `START=node server.js` in
[`vertracloud.config`](/configuration); a build step becomes `BUILD=`.

## Step by step

<Steps>
  <Step title="Deploy a copy">
    Upload a `.zip`, import the repository from [GitHub](/deploy-github) or run `vertra deploy`. Keep
    the old host live and don't touch DNS yet.
  </Step>

  <Step title="Copy the environment variables">
    Recreate them in **Config**, leaving out `PORT` and `HOST`, which the platform sets. It's a good
    moment to rotate secrets instead of copying them.
  </Step>

  <Step title="Move the database">
    Create the database, then export and import with the engine's own tools: `pg_dump`/`pg_restore`,
    `mongodump`/`mongorestore`, `mysqldump`. For Redis, recreate the keys you need or let caches warm
    up again. Connect with TLS as shown in [Connect a database](/guides/connect-database).
  </Step>

  <Step title="Test the copy">
    Use the `*.vertraweb.app` address and exercise the flows that matter while watching the **Logs** tab.
  </Step>

  <Step title="Move the traffic">
    Put the old application in read-only or maintenance mode, run a final data sync, then point the
    DNS at Vertra Cloud with a [custom domain](/guides/custom-domain).
  </Step>

  <Step title="Retire the old host">
    Keep it for a few days as a fallback, then shut it down.
  </Step>
</Steps>

<Tip>
  Lower the TTL of your DNS record to a few minutes a day before the switch, so the change (or a
  rollback) propagates quickly.
</Tip>