Unless you're using arrays. They went with "predictable" over "sensible" here.
> is flawless from my experience
As a heavy Kotlin user, I'd say it's far from flawless (not sure if you mean interop or the entirety of the language, but applies to both). I'm often creating and starring YouTrack issues. But yes, it's still a highly recommended alternative to Java.
Assuming it's for the JVM, you should definitely choose Kotlin for your next project. Most of the flaws I find are for advanced usage (e.g. interop, coroutines, etc) or tooling (e.g. gradle issues, dokka) or just general advanced language use. I don't keep a running list of issues (I made one back in the day [0] but not all of it is still applicable), but nothing would keep me away from the language. It made a lot of right decisions.
Jetbrains has a very good 4 weeks free course on Coursera https://www.coursera.org/learn/kotlin-for-java-developers.
We’ve beginning to introduce Kotlin in our code based, and also begin to use Kotlin Dsl on our new Gradle projects; for the moment, the experience is excellent.
Interop with Java is really good and the support from IntelliJ is also fine.
Unless you're using arrays. They went with "predictable" over "sensible" here.
> is flawless from my experience
As a heavy Kotlin user, I'd say it's far from flawless (not sure if you mean interop or the entirety of the language, but applies to both). I'm often creating and starring YouTrack issues. But yes, it's still a highly recommended alternative to Java.