CQRS by Example

The Full Picture

In previous chapters, we zoomed in on every necessary component to make a CQRS architecture work. Although this approach provided detail about each building block — such as Commands, Queries, and Projections — it’s time to zoom out and design a complex end-to-end use case: the Timeline.

The Timeline Use Case

A central part of Cheeper — and also of Twitter — is reading what other Authors say. All the Authors someone follows make up their Timeline, which is a collection of Cheeps in chronological order and unique to the owner of the account. When someone joins the platform, they won’t have any Cheeps to read, so Cheeper — or Twitter — may suggest people follow popular Authors to start building their Timelines.

In terms of performance, ...