Echoing what other people have said here and adding my own recommendation. - Dont use Medium, they will paywall your users and you cant use your own domain -

Echoing what other people have said here and adding my own recommendation. - Dont use Medium, they will paywall your users and you cant use your own domain - Dont roll your own, it will waste time and marketing will get mad. - Not sure about substack tbh so My honest recommendation is to use Ghost, it has the highest quality themes and CMS (when compared to wordpress) and you can self host if you'd like or let someone else take care of the mess for a small fee.