This may be a stupid question. It seems like the spring folks seem to like kotlin quite a bit. What is the roadmap with respect to kotlin? Is the idea to take advantage of kotlin under the hood and allow users to do whatever they want with that? Is the idea for it to be more first-class support for kotlin? I saw there were the jafu and kofu things both being developed. In say a year or two, do you anticipate a lot of users starting new spring projects to be using kotlin, or do you expect that most people will still be using java?

Our focus is to provide first class support for both Java and Kotlin. That includes for example Coroutines support, providing code sample in both languages this year. Kofu is the next step by providing an even more Kotlinish way of configuring your applications, but we have not decided yet if and where that should live in a non incubating mode. I do not make plans about how much will use Java and how much will use Kotlin in 1 or 2 years, it is up to users to decide 😉

Agreed. I think your argument for better WASM support makes a lot of sense

FWIW, at last year's KotlinConf talk, I did a quick poll of Spring users and most of the room raised their hands. (EU folks appear to adopt new stuff a lot faster than US folks.... Especially the banking industry) Kotlin is going to be a major part of Spring....if you read their blog, that's fairly evident as well.