Scala can be made to scale, and you have access to a rich ecosystem of libraries, including the universe of java, which is nothing if not vast.

at the same time, the complexity of scala leads to idosyncratic implementation, especially from those new to the language, or at least new to complex type systems. this means you feel good at first, but as your project grows, building the arch two legs at a time from the ground up, sometimes they will not meet in the middle the way you expected. I don't think this is unique to scala, just worse than other choices. this effect also makes it much harder to collaborate with other devs on your project.

I find that Go is very performant and scales equally well. the overhead to run a Go executable is generally orders of magnitude less than the price of getring the jvm up and running. concurrency and parallelism are built in features of the language. I've saved eons of time by avoiding the crazy-making ways of Akka. and the language is small by design, hence the name, a game with few rules. all of this makes Go ideally suited for team projects.