I was thinking about adding a new technology to my current stack (Ruby and JavaScript). But, I want a compiled language, mainly for speed and scalability reasons compared to interpreted languages. I have tried each one (Rust, Java, and Kotlin). I loved them, and I don't know which one can offer me more opportunities for the future (I'm in my first year of software engineering at university).
Which language should I choose?
It depends on which level and use cases you prefer to work at. Close to the machine? Rust is great but if you need to find more job opportunities, then take C/C++. Java has many job positions but I suggest Kotlin over it. Think about it as a better Java, but fewer job positions. Do you want to do your own projects? So a productive language like Ruby is way better. Like to program front-end apps? Take JS. Find your passion.
I will highly recommend Kotlin. I have worked with all three intensely and so far the development speed and simplicity is the best with Kotlin. Kotlin supports coroutines out of the box. Now, it isn't something that can't be implemented in other languages but Kotlin makes it super easy to work with them. Kotlin has a bit of learning curve, so, by the time you can actually use it idiomatically chances are that you will get proficient in Java too. But once you get it, you get it, then there is no other language ;) Kotlin is backed by Google and Jetbrains team so you can expect latest programming features and good community support.
Dev Stack makes some good comments. Kotlin does have a learning curve, but once you have learnt it you will develop quality code faster.
