How to build a React+redux+RubyOnRails app?

Question

Ruby on Rails

The project is not small and, based on past experience in writing web applications, I decided to do everything right right away and chose such a React + redux + RubyOnRails technology stack for myself. But in the course of development, the question arose, how to synchronize the actions of the backend and frontend? In one project, they simply separated the logic and used middleware for .fetch () data from the Redux side and sent responses in the form of json from the server side, I thought it might be worth completely separating the logic and switching Rails to api mode? Maybe someone will share their experience, I don’t want to complicate the project at the stage of building the architecture ...
UPD: While we are using cells, each major react component (chat, profile, etc.) is a separate cell that I connect to the view. Or is it better to use a complete React app?