Hello!
Command
meteor build --directory /app-compiled --allow-superuser
very slow (10-15 minutes).
But in develop mode, changing a file, “hot reload” takes only (1-5 seconds).
How to fast rebuild meteor app when changes 1 js file?
As a rebuild it only compile the changes and not the rest. You can see many includes in the header.
When you build, meteor compiles every thing in 3 files so it can be run by node.
This is why it’s more costly.
If you want fast changes on a testing environment, I recommend you run your app in development mode on the testing server with auto pull from your git on a named branch 