> - Greytext types that are inferred are super useful. I do wonder how I'd do if the IDE didn't tell me what the types were. But it basically means you get all the benefits of type annotation without having to write out the types.

Actually the strong-type-inference plus greytext thing is one part of Kotlin where I'm not sure what to think about it.

When I first saw Kotlin examples on the internet with all the "it.something" I was "What is going on there?!? What is that supposed to do".

Then the first time I tried writing Kotlin myself everything became super clear due to that Greytext shown in IntelliJ. However 80% of the time I'm looking at code is not in an IDE. It's either on code reviews or in the browser (github, internal code browsers, etc). All the information is not available there, and one has to be aware again what the implicit types will be.

The challenge certainly also exists in other langues with type inference (auto in C++, var in Java/C#, inference in Rust, etc), but for some reason I found it worse in Kotlin. Maybe due to the commonly used methods which take a closure/interface as last parameter, and and the fancy builders.