cqrs-implementation

CQRS is an architectural pattern that separates command and query models to optimize systems for high-performance writes and fast reads. It enforces distinct handlers, event stores, and projections to keep read models synchronized via events.

To implement event-driven projections, you apply CQRS by dispatching commands through handlers that update an event store. Projections then consume these events to update the read model, ensuring complex querying and synchronization.

You need CQRS for scalable architecture when your systems require high-performance writes, fast reads, and evolving read/write models. It is suitable for event-sourced systems and architectures handling growing data volumes with flexible data models.

CQRS does not strictly require event sourcing, but they are frequently combined. CQRS separates read and write workloads, while event sourcing uses an event store and projections to keep read models in sync for event-driven behavior.

The best way to start is to create a minimal CQRS skeleton and dispatch a command, such as CreateOrder. This verifies the separation of write and read models by testing distinct command handlers and event-driven projections.

The main limitation of separating command and query models is the added architectural complexity. Maintaining distinct handlers, event stores, and projections introduces synchronization challenges and requires careful management of event-driven updates.