I used Ember once, took over an Ember project from a very good Ember programmer. I found I have to duplicate the models from database, to ORM in backend, and Ember. Everytime I have to modify/add a database column, I have to modify 3 places. So I end up get ride of Ember and use Flask-Admin only. Even better, I get ride of the ORM in Flask too, using reflection. Then my code is 3 times less, and I feel happy.