Do you have some way of sharing non-UI code between native mobile clients, e.g. Xamarin, RoboVM, or something JavaScript-based? React Native would be particularly appropriate here since you&#x27;re using GraphQL and looking at Relay. Rewriting non-UI client code in two or more languages is unacceptable in my view, because it either encourages dumb clients, which is the opposite of what you want if you&#x27;re using GraphQL, or leads to subtle discrepancies between platforms.