In the new RedMonk Index 1/2018 Kotlin performs well:
As we noted in our last run, the combination of Kotlin’s attractiveness to Java developers and its elevation to first class citizen on the Android platform seemed to indicate the language was poised for a major jump. In the course of little more than a year, Kotlin has gone from #65 to #46 in our Q3 run to #27 as of January. It didn’t quite match the performance of Swift, which managed a #68 to #22 jump in half that time, but Kotlin is now the second fastest growing language we have seen after Apple’s successor to Objective-C. Interestingly, the two languages have taken distinctively different paths to their respective rankings. […] Either way, Kotlin is one of the fastest growing languages in the world at present, and for good reason. What will be particularly interesting to watch is whether Kotlin can achieve a foothold in mainstream enterprise applications. This would give it an avenue for growth that Swift lacks at present.