Why should you care?

ShopNest write path wants normalized integrity; the product list wants denormalized speed.

See it live — copy this example

Sketch the architecture on paper. These lessons focus on concepts and trade-offs.

Command: PlaceOrder → Orders DB (normalized)
Event: order_placed → updates ReadModel OrdersByUser (denormalized)
Query: GET /users/me/orders hits read model

Lag: read model may trail writes by milliseconds–seconds

Run Example »

This lesson uses terminal or setup steps. Run commands on your computer — the live editor appears on coding lessons.

What happened?

• You accept short read lag for query speed.
• Keep commands validated against the write model.
• Do not force one schema to serve both awkwardly.

Practice next

1. Identify one ShopNest read that hurts the write schema.
2. Build a read table/projection updated by events.
3. Document eventual lag to the UI team.
4. Add a “refresh” primary read after write for confirmation pages.
5. Version read model schemas.

Remember

Split read/write shapes. Project via events. Accept small lag where OK.

Order history read model

ShopNest serves history from a denormalized store.

Outcome: Checkout writes stay simple; history stays fast.