Book: Hexagonal Architecture in Go Also by me: Thinking in Go (2-book series) — Complete Guide to Go Programming + Hexagonal Architecture in Go My project: Hermes IDE | GitHub — an IDE for developers who ship with Claude Code and other AI coding tools Me: xgabriel.com | GitHub A team I talked to last spring shipped a "simple" checkout flow. The order service called the inventory service, then the payment service, then the shipping service. Three HTTP calls in a row, inside one HTTP handler. It worked in staging. It died in production the first time the payment service returned 504 after the card was charged but before the response came back. The order showed failed . The customer's card was charged. The warehouse never reserved the item. Three different systems, three different stories, no single place to ask "what happened?" . That flow needed a saga (the saga pattern, originally described by Garcia-Molina and Salem in 1987 — paper ).…