Ktor

Ktor is an asynchronous framework to create microservices and web apps in Kotlin. It’s an extensible framework with a configurable pipeline that lets you add the extensions you want when you need them. What’s best about it you can create highly scalable apps using Kotlin coroutines, leveraging the non-blocking development approach. 

A microframework is a term used to refer to minimalistic web application frameworks. It is contrasted with full-stack frameworks.