At TouK, we try to early adopt technologies. We don’t have a starter project skeleton that is reused in every new project, we want to try something that fits the project needs, even if it’s not that popular yet. We tried Kotlin first it mid 2016, right after reaching 1.0.2 version. It was getting really popular in Android development, but almost nobody used it on the backend, especially — with production deployment. After reading some “hello world” examples, including this great article by Sebastien Deleuze we decided to try Kotlin as main language a new MVNO project. The project was mainly a backend for mobile app, with some integrations with external services (chat, sms, payments) and background tasks regarding customer’s subscription. We felt that Kotlin would be something fresh and more pleasant for developers, but also liked the “not reinventing the wheel” approach — reusing large parts of Java/JVM ecosystem we were happy with for existing projects (Spring, Gradle, JUnit, Mockito).