Front-end on a different domain I'm using drupal8 in headless mode.
So I have a backend on Drupal8, and a frontend in JS.
I'd like to have content URLs in drupal8 to point to the frontend domain and not the backend (which doesn't have any templates to display the content).

backend.example.com/mycontent for Drupal8
www.example.com/mycontent for the frontend

How can I do to update all the links in UIs to have the frontend domain in place of the backend domain ? (views or admin/content or breadcrumb on edit form).
You can try using the Domain access module that does the work. Version 8.x works with not issues. Go ahead and use it with no fear.