SBT is hellish though and the added complexity that Scala has imposes a lot of cognitive overhead.
With Kotlin, you always end up writing cleaner Java and don't risk erring on the side of unneeded entanglement in the spaghetti monster that Scala can sometimes be.
> the added complexity that Scala has imposes a lot of cognitive overhead.
That's just FUD and memes. Scala is more consistent than Java and much more consistent than Kotlin, which makes it much easier to concentrate on what your code is actually doing.
(This is why you will see some very complicated functions and datatypes written in Scala - it's only really practical to write a complicated function or datatype in a simple language, because otherwise the language will sap too much of your attention. But that's a reflection of those functions and datatypes; if you don't need a complicated function or datatype, don't use it. The language itself is simple)
> With Kotlin, you always end up writing cleaner Java and don't risk erring on the side of unneeded entanglement in the spaghetti monster that Scala can sometimes be.
Not true. Kotlin codebases that do the same thing look worse than Scala codebases or have subtle misbehaviours waiting; Kotlin has a huge number of ad-hoc special cases e.g. nullables, async, continuations are all special language features. Kotlin's ability to do error handling/validation is actually worse than Java's (no checked exceptions and no adequate replacement if you want to actually report the details of failures).
> the added complexity that Scala has imposes a lot of cognitive overhead
Scala definitely gives you enough rope to hang yourself, but in my experience this is no different than any other programming language. It's not like e.g. annotation processing tricks popular in the Java world are that easy to grasp.
Scala has some advanced language constructs, but they are commonly used in the same way for the same problems instead of the ad-hoc hacked-together solutions you get in languages not offering enough support.
Before going multi module and needing special control on the build process and having a LOT of code, what exactly hellish do you think someone and a beginner at that will encounter? I have been writing it professionally for 5 years and I find it ok.
For starters, it's build time is rather slow, produces really fat jars of I recall well, and I find the whole code as configuration SBT files complex and easy to get wrong.
you can use maven with Scala without too many headaches.
"spaghetti monster that Scala can sometimes be" -> I'd like too see an example of a Java snippet that in Scala you can express only with a higher degree of spaghettosity.
