Shifting Gears: From Events to Event-Driven • Ryan Cormack • GOTO 2024

Event-driven architectures (EDAs) help build systems with low temporal coupling, allowing services to work independently without strict dependencies

Moving to event-driven requires more than just technical changes - it needs alignment across product, engineering and business teams through shared understanding and communication

Start small with “minimum viable migrations” - identify bounded contexts and make incremental changes rather than big bang transformations

Events should represent business facts and state changes, not internal implementation details or database schema changes. Events are a contract and should not have breaking changes

Use event storming workshops with cross-functional teams to model business processes and identify event boundaries and patterns

The cloud provides many managed services that help build event-driven systems cost-effectively, with pay-per-use pricing and built-in scalability

Build isolated systems that can evolve independently - new features should be able to consume events without impacting existing core services

Focus on asynchronous communication patterns and queue-based architectures to handle failure scenarios gracefully

Implement proper monitoring, observability and documentation around events to build trust and understanding across teams

Share knowledge and patterns across teams but allow independent implementation within bounded contexts - empower teams while maintaining consistency

Consider cost and reliability as key features - design systems to only run and scale when needed while maintaining resilience

Events can have multiple consumers but producers shouldn’t need to know about them - this enables flexible system evolution