The Dll and DllReference plugins allow the code to be split in multiple bundles in a way the bundles can be compiled independently.
It is possible to build "vendor" scripts in a library that does not need to be compiled often (ex: React, jQuery, Bootstrap, Fontawesome...) and reference it in your app bundle that will need those scripts.
The application bundle, the one that is constantly going to be changed, will be in a separate configuration just referencing a already built "vendor" bundle.