Event Sourcing and CQRS: Log First, Views Derived

Event Sourcing and CQRS: Log First, Views Derived A data-flow diagram generated by Archify. 01 / Commands 02 / Validate 03 / Event Log 04 / Materialized Views 05 / Reads Client App · book, cancel · 01 / Commands · user action Client App book, cancel user action Command Handler · validate, then emit · 02 / Validate · rejects invalid Command Handler validate, then emit rejects invalid Event Log · append-only, immutable · 03 / Event Log · source of truth Event Log append-only, immutable source of truth Booking View · status per booking · 04 / Materialized Views · projection Booking View status per booking projection Dashboard Charts · organizer metrics · 04 / Materialized Views · projection Dashboard Charts organizer metrics projection Badge Files · print-ready output · 04 / Materialized Views · projection Badge Files print-ready output projection Support UI · look up bookings · 05 / Reads Support UI look up bookings Organizer View · charts and counts · 05 / Reads Organizer View charts and counts Badge Printer · on-site printing · 05 / Reads Badge Printer on-site printing command request append event fact, past tense booking view projection chart data projection badge files projection query view read query view read render badges read Legend primary data async batch data store data flow