What exactly in Kotlin language attracts you or seems to be its advantage?

Kotlin attracts several key advantages:

• Conciseness and expressiveness: less boilerplate code compared to Java, thanks to smart types, extension functions, data classes.
• Type safety and null safety: built-in system prevents NullPointerException errors at compile time.
• Java interoperability: existing Java libraries can be used without issues.
• Coroutine model for asynchronous programming: simplifies writing asynchronous and concurrent code.
• Modern language features: such as higher-order functions, lambdas, smart casts.

Example of a data class and coroutine:

data class User(val name: String, val age: Int)

suspend fun fetchUser(): User {
    // simulate asynchronous operation
    delay(1000)
    return User("Ivan", 30)
}

These features make Kotlin a convenient and modern language for development, especially in Android.