Definitely go for kotlin if you want to write a GUI. I'd also recommend Kotlin (or maybe go, never used it) if you want to write a server. Rust has ambitious but not there yet server frameworks, and it's quite hard to go off the beaten track with most Rust server frameworks (say if you want to write your own little cache layer).
I'm just a student, but I have the impression rust isn't a good choice for maximizing career prospects. Still writing it, because I love it.