Ok, try to go off the well trodden path of a default systemd setup.

Eg. make your system "login interactive" before networking and other unneeded services (database, web server, whatever) are even attempted to be set up/started.

Use just drop-in configuration fragments (*.service.d/override.conf) without making an unmaintainable mess (ie. without making your own copies of whole, OS installed unit files).

That should get you the feel. :) And it's not something crazy, it's just basic re-ordering of dependencies.