Unidirectional Data Flow (UDF) is a powerful technique that enhances our Reactive apps to work deterministically. Synchronising our views with fresh data was never an easy task to accomplish. For this same reason, there are mechanisms that support us to make that possible. Surely callbacks were a thing in the past, however, they were an antipattern themselves due to the lack of readability. Now we don't need to deal with them any more thanks to Kotlin Coroutines. Getting ready for Declarative UIs with Kotlin Coroutines and friends is indeed feasible, now we could use suspend functions, Flow and in the end StateFlow would make our Reactive apps ready for Declarative UIs. Let’s define a single entry point, receive data, transform it into a state, and render each state. Let’s get our apps ready for a Declarative UI world on Android.