Android developers used to deal with XML to build UIs even if they love or hate. It can be very time consuming and sometimes hard to maintain if Designers requested very customized UI components or PM requested very dynamic UIs. Now, Jetpack Compose comes out and it helps developers to build UIs in declarative way. It can also be used together with XML, too. The potential of Jetpack Compose is limitless. I will present some under the hood stuffs, the potentials and how to integrate in existing apps.