The receivers mechanism is kind of nice; reminds me of this[0], except that in Kotlin, everything is still statically typed. It's a really clean way to implement Trygve Reenskaug's DCI architecture.

[0] http://www.p-cos.net/documents/contextl-soa.pdf (there was once an article called "ContextL : The Holy Grail of Business App Development", but this seems to be no longer available