Event Sourcing Architect

What it does

This skill enables AI agents to design and implement robust architectures based on event sourcing principles. It covers key aspects like event store design, CQRS implementation, projection building for optimized reads, saga orchestration for complex workflows, and managing eventual consistency. The agent can guide you through the process of creating systems that require complete audit trails or temporal querying capabilities.

When to use it

• Building applications requiring comprehensive audit trails of data changes.
• Implementing intricate business processes involving compensating actions (e.g., rollbacks).
• Designing systems where querying historical states ("what was state at time X?") is essential.
• Creating event-driven microservices architectures.
• Separating read and write models to optimize performance.

Key capabilities

• Event store design and implementation
• CQRS (Command Query Responsibility Segregation) patterns
• Projection building and read model optimization
• Saga and process manager orchestration
• Event versioning and schema evolution
• Snapshotting strategies for performance
• Handling eventual consistency

Example prompts

• "Design an event sourcing architecture for a customer order management system."
• "How can I implement sagas to handle distributed transactions in my microservices?"
• "What are the best practices for versioning events in an event-sourced application?"

Tips & gotchas

• Immutability is key: Never modify or delete committed events in production environments.
• Projection rebuilding: Always rebuild projections in a staging environment before deploying changes to production.
• Event Size: Keep events small and focused for better maintainability and performance.