Don't you still need Futures for async stuff in order to not block the thread, or is each request handled by a lightweight 'fiber' (erlang process/goroutine)?
That's correct, blocking operations within an actor need to be wrapped in a Future[1]. But Akka itself can be extremely performant if the bulk of your processing is non-blocking. Any non-blocking or long-running operations should be executed in a separate thread pool (if there are many), or just a separate thread.
