Good article, thank you.

Nowadays you can also use method references in Kotlin so:

val driversLicence: DriversLicence? = car?.driver?.let {

licenceService.getDriversLicence(it)

}

becomes simply:

val driversLicence = car?.driver?.let(licenceService::getDriversLicence)

Note that I also removed the type declaration, the compiler will infer it as DriversLicence?