If you are an Android Developer, chances are you are pretty excited about Jetpack Compose! But how does it work? In this talk, we will take you along the journey of a Composable function, from being written, going through the unknown lands of the Kotlin and Compose compilers to being executed and displaying UI! From Composables all the way down into the compiler plugins, we expose the metaprogramming responsible for all the "magic". Whether your interest is Jetpack Compose, compilers, or code transformations, this talk takes an otherwise complicated topic and makes it digestible for everybody by diving into specific features offered by Compose. By examining Compose's snapshot system, you'll follow the compiler phases down to intercepting code transformations with IR. By recognizing the patterns that make it hard for Compose to generate efficient code, and this can help us to recognize patterns to use for performance.