[toast0]

> I think architecting an Erlang system can be kind of tricky because you do have to think about all these processes sort of co-existing at the same time and how they interact.

I find it easier to think about each process in isolation --- what messages does it get, and what does it do with them; if it needs to send messages, who/where does it send them to and what will it get back, including errors or timeouts and not worrying about what the other process does in the moment.

The overall behavior of a system built from communicating processes can get hard to predict though. You build up observations, intuition, and escape hatches over time.