I’ve developed systems in Java (and C etc) since 2013, and I can truly say Kotlin makes my job easier. Now it isn’t about Kotlin being better than Java, it’s just that Kotlin is a lot more fun than Java. I enjoy it more.
It took me one work day to get up and going in Kotlin, 4 days less than the average Pinterest engineer apparently. I’ll be honest with you though, I began writing conventional Java in Kotlin. And I loved every line of it.
For me the transition has been really natural and with the thorough IntelliJ support one can pretty much continue writing Java without semicolons, if one wishes to do so. The cheer fun of Kotlin will turn the most stubborn Java certified CISCO engineer into a Kotlin freak though, don’t worry. It’s just a matter of time.
Ugh TLDR; I’m a sucker for Kotlin.