Kotlin with Hadi Hariri
Whatever engineering problem you have right now, the solution is probably not to write a new programming language. But sometimes it does make sense.
JetBrains makes IDEs–the interactive development environments that many people code in, like IntelliJ and Webstorm. And all of these IDEs are written in Java. So the JetBrains team is very familiar with Java and the JVM. Since JetBrains spends so much time working on tooling for developers, they also have an intimate understanding of the problems that developers encounter.