Kotlin vs Java
First to start off they are both great languages to use. Java has been the go to language for developing backend systems since its inception 20 years ago. In the near to long term, it will continue to be a major player in the software industry. However, there have been a lot has changes with the Java ecosystem in the past few years.
Oracle has began to build a wall around Java with their shorter LTS windows and new languages have challenged Java's rule. Google's decision to make Kotlin a first class language has accelerated its adoption. Kotlin has done right by being a less-verbose, safer Java, which is more new user friendly than Scala's attempt to avoid any relation to Java. Kotlin code is far more concise than comparable Java code.
Personally I believe there is a place for both languages. I think Java will continue to be a popular language for years to come, but that might not be the case forever, as Kotlin continues to grow.
Do you program in Kotlin or Java? Let me know your opinion!