This is the first time that JetPack Compose has been used outside of Android. Why is the web implementation creating/updating the UI on the server? Web Sockets would be the main bottleneck. Would be much more efficient to create/update the UI on the client, and let the web browser/JS APIs do the heavy lifting just like Fritz2 ( https://www.fritz2.dev/ ) has done.

Server-side rendering is the least efficient approach to creating/updating web UI's.

JetBrains have their own UI framework (currently in development) which isn't based on JetPack Compose, and is being used as part of their new IDE platform ( https://www.jetbrains.com/careers/jobs/senior-software-engineer-new-ide-platform-442/ ). Most of the new IDE platform is written in Kotlin and no Java is used. Reasonably safe to assume that the new IDE platform isn't dependent on the JVM. I'm guessing that the new IDE platform is using Kotlin Native since a small part of the platform is written in Rust. Presumably Kotlin Native will have Rust interop in the near future.