Implement CQRS

write model with read projections

Challenge 4 of Data PipelinesAdvanced~55 min

Split the model that changes data from the models that read it. In CQRS, commands go through a write model that validates and emits events, while queries are served by separate read projections shaped for exactly how they're viewed. Build the write model that decides and applies events, denormalized read projections, and the command bus that wires them together. The architecture that lets reads and writes scale independently.

4 steps

1. 1The Write Model's State
2. 2Deciding Commands
3. 3Read Projections
4. 4The Command Bus