I wonder how much of your comment follows from past experiences with other compile-to-JS languages. Scala.js solved all the problems you mention. * Performanc

I wonder how much of your comment follows from past experiences with other compile-to-JS languages. Scala.js solved all the problems you mention. * Performance is on par with hand-written JavaScript. * The compiler and optimizer are incremental so they compile your code in 1-2 seconds for significant codebases. * Interoperability is as easy as in TypeScript: just use type definitions for external JS libraries and then transparently call them. It's all explained from the big boxes on the page of https://www.scala-js.org/ https://www.scala-js.org/ Don't let your past experiences give you wrong impression of Scala.js.