A few notes about the technologies we are using:
* React Native (duh), supporting both iOS and Android
* ASP.NET C# Web API
* SQL server
* Team City
* Push notifications & SMS services
* Some light web based stuff
For our test environment we use Testflight (iOS) and Play Story Beta Testing to deploy binaries to staging, but we use React Native Code Push (https://github.com/Microsoft/react-native-code-push) for any changes that don't require new binaries - great for rapid deployment!