thanks @alex_melkoff for your feedback. I am not sure whether you are right about ERPNext being the monolithic block you suspect it is.
If you look at the manual install instructions you can at least clearly see which components it is build from (you are probably aware if those). I would assume it should be possible to have those function together as separate services should be possible.
In this topic ERPNext in 2014 and in 2016 - #9 by chlarsen such separation (not docker specific though) is being discussed (and at least partially solved) I think.
@chlarsen @anand where the main contributors to that issue. Can you two maybe share some insight on the separation of services here?