It's a cool series. Mostly review for me but I certainly passed it to my team to review. Ultimately I say that 99% of the time the correct answer is to not use raw threads and never share memory. There are much better concurrency and parallel patterns out there. Akka(.net in this case), Coroutines and Channels, Erlang Actors, Clojure's core.async, .net's async/await even. Honestly if you are reaching for threads you probably should ask yourself if some other way would be better and safer.