Kotlin is the official Android programming language. As much as Java is still a popular language in the native Android development space, Kotlin is slowly overtaking it with most of the new apps being written in Kotlin. Kotlin is faster and simpler to write than Java as it is less verbose and comes with tons of syntactic sugar. It has vast documentation and a fast-growing community to offer support to its developers.
Android apps originally written in Java are continually being migrated to Kotlin. Kotlin is totally interoperable with Java and module integration is very common. Developers who can code in both Kotlin and Java come in handy when testing and debugging collaborative inter-op projects.
