Status: IN
Observer's three independent notification design decisions (push/pull model, broadcast scope, lifecycle safety) represent fine-grained engineering concerns of event architecture that complement Command's temporal reliability engineering (hysteresis prevention, meaningless-undo filtering, state-variant copy management) — Observer addresses spatial notification design while Command addresses temporal persistence reliability, suggesting that production-grade event architecture involves both spatial and temporal engineering dimensions.
Observer's spatial notification engineering + Command's temporal reliability engineering = complete event architecture engineering surface
Depends on (SL): observer-notification-three-design-decisions, command-exemplar-of-engineered-event-architecture