This year at Google I/O a new declarative UI framework Jetpack Compose was announced. After that Apple presented SwiftUI for iOS on WWDC. Declarative UI suddenly became a hype topic.
You definitely know that such approach in Android isn't new — there are lots of DSL wrappers on top of regular views. But what if the real declarative UI is not the future with wait for Compose's stability, but a present thing? I will tell you about Litho — UI framework from Facebook which is responsible for fast rendering of heavy UIs in apps with billions of downloads.
We will talk about Litho's usage, things that happen under the hood and will finally answer the question: is it really impossible to work with UI from more than one thread?