I have an app that is already started in PM2, now I want PM2 to be restarted with a new version of this app, meanwhile, it takes some time to build and serve the app.

the current behavior is that PM2 stops the process and the website goes down for a while until the new version is started

I need the current version to continue running until the new one is ready for listening.

also, after starting the app with pm2, and when I run pm2 status, I see the app is running, but it still building and not yet listening to the desired port. how can I configure it to indicate a pending status if my app is still in the building phase?