Introducing enhanced custom event buses in Amazon EventBridge for enterprise-scale event-driven applications

Organizations building event-driven applications on Amazon EventBridge typically start with a single custom event bus in one account. This works well when a single team owns the architecture. As adoption grows across the organization, though, things get complicated. AWS best practices recommend a multi-account structure, which means each team runs in its own account. To route events between them, teams create multiple event buses connected through cross-account rules or bus-to-bus configurations. This workaround reintroduces the operational complexity that serverless architectures are meant to eliminate.