No, you don't. I've been working on Scala project with a team mostly comprised of people who never used Scala before and who came from different programming ba

No, you don't. I've been working on Scala project with a team mostly comprised of people who never used Scala before and who came from different programming backgrounds. We can and do ignore huge portions of the Scala language and ecosystem (no Scalaz, no type system hackery). At the same time, we still reap huge benefits from the parts of Scala we do use. Immutability by default, high-level parallelism/concurrency constructs, monads, typeclasses, etc.