I agree that the tooling is getting better. Some of the popular libraries are still figuring out the right patterns to apply to make them more "Kotlin friendly"

I agree that the tooling is getting better. Some of the popular libraries are still figuring out the right patterns to apply to make them more "Kotlin friendly". Tools like the Checker Framework [1], JSR 308 [2], and compiler plugins like Traute [3] can also help with the safety issues on the Java side. Kotlin is beginning to understand these more, and some of the basic annotations are supported, but the tooling is only going to improve with all of the backing that Kotlin currently has. [1]: https://checkerframework.org/ https://checkerframework.org/ [2]: https://jcp.org/en/jsr/detail?id=308 https://jcp.org/en/jsr/detail?id=308 [3]: https://github.com/denis-zhdanov/traute https://github.com/denis-zhdanov/traute