I worked with Scala at my job for 2.5 years. In brief, if you really want (or need) to be on the JVM, then use Scala. It's everything that Java should have been

I worked with Scala at my job for 2.5 years. In brief, if you really want (or need) to be on the JVM, then use Scala. It's everything that Java should have been, and after you get comfortable in Scala, you will never want to write a line of Java again. However I have to agree with many of the common criticisms. My last team had many WTF moments with the language. We also suffered from poor type inspection and IDE support, failed attempts at writing an SBT plugin, and slow compilation. Having access to Maven repos is great, but using Java libraries is often a frustrating experience where you end up having to write a whole wrapper library around the Java lib just to work with something idiomatic. The language is a great stepping stone to bring hardcore Java devs into the world of FP, but honestly, if you don't need the JVM, I would rather be using Haskell.