I've never got the hate for Maven - all the design decisions people dislike seem to be the same things that people praise Cargo et al for. If anything it suffers for being ahead of its time.

Use the Scalor plugin, https://github.com/random-maven/scalor-maven-plugin, and then Scala.js just works. I actually hooked it up to Netlify by treating Maven as a static site generator: http://m50d.github.io/2018/11/29/deploying-scalajs-with-netl...