Push a Next.js app and Deplo builds it, runs it as a Node server and puts a certificate in front of it, on a server you own.
Detection runs on every deploy and is never stored, so a change to the project is picked up by the next push.
Short answers to what comes up before moving a Next.js app onto your own server.
Yes. The app runs as a Node server in its own container, so server components, route handlers and middleware behave as they do locally.
In the app's settings, per environment. They are available during the build too, and secret values are write only: nothing reads them back.
No. The new container has to pass its health check before the old one is retired.
Answer three questions and pick a host, or install Deplo on a server you already have. It's free, and leaving is as easy as arriving. What you do with the money you save is your business.