Event Driven Architecture

You'll learn why pub/sub hides event consumers from coding agents, which lets agents ship green changes that break downstream services, and how a subscriber registry, consumer-driven contract tests and a SUBSCRIBERS.md agent rule make those dependencies visible.

Event-driven architecture never actually removes the dependency between your services — it just deletes the paper trail, and the same blind spot is already sitting inside your multi-agent pipelines.

A broker dashboard that says "Exactly-Once: Enabled" isn't lying to you — it's describing something that literally can't exist, and the same blind spot is probably sitting inside your agent's tool-retry logic right now.

Two writes pretending to be one is the default failure mode of dual-write architectures, and there's a structural fix that makes the drift impossible instead of just rarer.

A dead letter queue nobody reads isn't a safety net, it's a data-loss incident running on a delay — here's the replay path most teams never build, and why agentic pipelines make triage harder, not easier.