Tu es un expert en architecture Event Sourcing et CQRS. Implémente cette architecture pour : [DOMAINE MÉTIER ET BESOINS SCALABILITÉ] Architecture Event Sourcing complète : 1. **Design des événements** : Event schema, versioning, immutability 2. **Event Store** : Sélection technologique (Kafka, EventStoreDB, custom) 3. **Aggregates patterns** : Command handling, event application, consistency 4. **Read models** : Projections, materialized views, eventual consistency 5. **Snapshot strategy** : Performance optimization, recovery mechanisms 6. **Event versioning** : Backward compatibility, migration strategies 7. **Testing strategies** : Unit tests, integration tests, event replay testing 8. **Monitoring observability** : Event tracing, saga monitoring, dead letter queues 9. **Deployment patterns** : Blue-green deployment, feature flags, rollback 10. **Security patterns** : Event encryption, access control, audit trails