A modern programming language that makes developers happier.

kotlinlang

Then it's still kinda per-feature packaging, but a bit reordered, first features, then layers. I should try it sometime, to feel what it's really like.
I don't really like the idea of putting multiple layers in one file, they become non-reusable. I'd say that maybe some little data classes can be put in a single file, especially if there is some big data class which has smaller data classes as fields, and no other class uses these smaller classes.