Contract-First Event-Driven Architecture on AWS

When event-driven systems grow past a handful of services, the biggest failures usually are not infrastructure failures. They are contract failures . A producer adds a field and a consumer crashes. A team renames an enum value and downstream processing silently misclassifies events. A “minor change” ships without coordination and turns into a production incident. In this post, I will walk through how I design a contract-first event-driven architecture on AWS with a focus on: Event versioning str