I find that the approach in akka-bootcamp/src/Unit-1/lesson1 is artificial. The reader sending itself a "continue" message feels spurious; the stimulus is surely successive external stimuli and not internal simulated events. I Would prefer a while loop to continue to accept input. Also the reader totally ignores the start/continue message content, and that for me represents a bad smell (i.e. bad judgement/analysis logic). Just my 2c!