Mastering millisecond latency and millions of events: The event-driven architecture behind the Amazon Key Suite

This article details how Amazon Key modernized their architecture using Amazon EventBridge to transform a tightly coupled monolithic system into a resilient, event-driven solution.

• Replaced legacy monolithic architecture with event-driven design using EventBridge
• Implemented single-bus, multi-account pattern for clear ownership and centralized governance
• Built custom schema repository as single source of truth for event definitions
• Developed client library with built-in validation and type-safe interfaces
• Created subscriber constructs library using AWS CDK for standardized integration
• Achieved 2000 events/second with 99.99% success rate and 80ms p90 latency
• Reduced service integration time from five days to one day (80% improvement)
• New event onboarding reduced from 48 hours to four hours
• Standardized client library eliminated 90% of common integration errors

Amazon Key's event-driven transformation demonstrates how proper architecture patterns, schema governance, and developer tooling enable scalable, reliable systems while significantly improving team productivity.