Scala and Kotlin have perhaps in the past been two types of software that were not often mixed but Alexey Soshin focuses his talk at Functional Scala around just that. He highlights that Scala is not just 'a better version of Java' and concludes that Scala code and Kotlin code can definitely exist in the same project; he suggests that we should not avoid using Unit, especially in return types.
This talk was given by Alexey Soshin at Functional Scala.