Well, you don't have to use those abstractions. But yes, it's a sad fact that when programming in Scala, the closer to Java-style you program, the faster your p

Well, you don't have to use those abstractions. But yes, it's a sad fact that when programming in Scala, the closer to Java-style you program, the faster your program will be. I haven't read this paper closely, but it looks like it's more measuring the performance of Akka, rather than the performance of Scala. Akka does reasonably well here compared to Erlang, so I don't think there's anything we can complain about. Could you get all of Akka's features with better performance if it was made in Java? I doubt it. Optimized Scala and Java code should be identical.