I think the sweet spot for using Kotlin is to adopt it as "Java with nicer syntax." If you try to embrace the ecosystem, a lot of tools and libraries are still

I think the sweet spot for using Kotlin is to adopt it as "Java with nicer syntax." If you try to embrace the ecosystem, a lot of tools and libraries are still immature as other folks have pointed out. But if you stick to the existing Java ecosystem and just use Kotlin for the syntactic niceties, it's great for readability and productivity.