Kotlin Flow is often treated as a prerequisite for modern UDF-based Android architecture. But reactive stream pipelines come with real cognitive overhead: operators, cancellation, and mental models that are easy to get wrong, hard to debug, and sometimes uncomfortably reminiscent of the RxJava days. Jetpack Compose comes with its own reactive state system that already handles change propagation for us, and it’s one of the reasons Compose code feels so simple. In this talk, we’ll take a deep dive into how this state system actually works, and explore the trade-offs of pushing it beyond the UI layer—by building a fully unidirectional Android application without using Kotlin Flow at all.