Book: Event-Driven Architecture Pocket Guide: Saga, CQRS, Outbox, and the Traps Nobody Warns You About My project: Hermes IDE | GitHub — an IDE for developers who ship with Claude Code and other AI coding tools Me: xgabriel.com | GitHub You saved the order in Postgres. The transaction committed at 14:02:11. Then you called kafka.Produce("order-placed", payload) . The broker was rebalancing. The call timed out. Your handler logged the error and returned. The order is in the database. The event is not on the topic. Three downstream services never hear about it: billing, fulfillment, customer-emails. The customer's card was charged. Their warehouse pick never happens. Your on-call gets paged at 3am with a ticket titled "where is my order." This is the dual-write problem, and an engineer I know spent six months chasing it before someone gave it a name.…