Does anyone have experience implementing a GraphQL server in Kotlin? I'm trying to get a sense of what my options are. My preference is to use Ktor for my server in general. I have seen https://kgraphql.io/ but I'm unsure, given the < 1.0 release version, whether this is production ready.

I did some experimenting but never got as far as actually running in production. GraphQL-Java on its own was enough for what I needed. But the Expedia libraries look pretty good if you want more functionality. They even have some examples using Ktor as the server.

Just found that, thank you. I think this is the best place to start

As a previous poster already wrote the Expedia libraries are a pretty good library. It pursues a code centric approach to backend graphql. You can essentially write your data classes and define accessing classes for it which are simply passed to the (ktor-)module configuration to register your queries / mutations / subscriptions. Et voila you have an automatically generated gql-schema which you can use for your clients and a configurable endpoint to send you queries / mutations etc. to. We have been using the library for quite a while now and the leverage that this code centric approach brings with it is quite neat.