Build and deploy without break running PM2 instance

I have a node.js server managed by PM2 in a Nginx production server. The code is written in ES6 so needs (yet) to be compiled.

I want to know what is the best way to avoid break the running instance while the compiler is running (if compiling in the server) or while copying the compiled files from local to server.

Or maybe a good way to go into maintenance mode or something similar.

via Lionel T