I still remember the first time a junior dev I was mentoring asked me, “why did the order service just… hang for 30 seconds and then crash the whole checkout flow?” The answer had nothing to do with their code being wrong. It had everything to do with how their service was talking to another service — and nobody had ever actually taught them that part. That’s the gap this post is trying to close. Not “what is a microservice” — you already know that. This is about the part t