Good practice of Managing Front/Back end

Hello guys i was thinking what is best practice to manage front and back end.
Forexample i have project name TodoApp so i basically make two folders server and client and make repository at github of TodoApp with both folders in.
But the problem is when i deploy it at Heroku , then i upload server folder to another github repository .

Now i have to manage two repositories first with TodoApp with two folders, and second server

Please show me the correct method to do it.