I think the topics should be split: you have 'networking' which is about connecting computers typically using TCP, UDP, RDMA, ... and 'distributed systems' wh

I think the topics should be split: you have 'networking' which is about connecting computers typically using TCP, UDP, RDMA, ... and 'distributed systems' which is about how to use connected computers to achieve something. And yes, both are difficult, but for other reasons: - networking is hard because the APIs are old, platform specific and probably don't behave very intuitively. So trying to build messaging systems on top of sockets is not simple, (but you will only find out after you've moved beyond the prototype stage). - distributed systems is hard because the odds of successfully exchanging messages aren't in your favour.