I've played with it a few times and have some example code that uses it for my elasticsearch kotlin library. I wouldn't mind some code review for that actually because I have a nagging feeling my use of co-routines & ktor is not quite as it should be:
https://github.com/jillesvangurp/es-kotlin-wrapper-client/blob/master/src/examples/kotlin/recipesearch/ServerMain.kt
Speaking of my es client, I presented this some time ago in the Kotlin meetup. But I might do another presentation if you need presenters
@Holger Steinhauer [Mod] I've been working on building out support for the query DSL lately and mapping that to a KotlinDSL.
Won't be able to make it tonight as I have some conflicting events.