The Composable Architecture (or TCA for short), is an architecture/library for building large, robust, and scalable applications. It’s built on a foundation of ideas popularized by Elm and Redux, but made to feel at home in the Swift language and on Apple's platforms. Further, it’s strongly opinionated about how to manage side effects and build end-to-end tests that guarantee your business logic is doing what is expected. In this talk, we are going to describe the benefits vs other architectures, and build a demo on SwiftUI applying the main concepts.