@Adam S maybe that one ^^^ I've had success introducing Kotlin to multiple teams that until that point only used Java, it's hard but possible
recommend always framing it as a "trial", and only doing it for something small, eg a small new service or pick an endpoint in an existing service and implement it end to end inside the same java project but in kotlin
then, people will either see the benefits, or they won't and you start looking for another job lol