Status: IN
The derived-system pattern (secondary indexes, materialized views, projections) depends on event infrastructure that is unreliable at its foundation: event sourcing has no durable recovery mechanism and conflates two ID spaces, while derived systems require explicit flush calls and old-value CDC events for consistency — the consumer-side correctness requirements depend on producer-side guarantees that do not hold.
Combines a depth-3 conclusion about event sourcing unreliability with a depth-1 conclusion about derived system requirements, exposing that the consumer pattern demands properties the producer cannot provide
Depends on (SL): event-sourcing-unreliable-in-persistence-and-addressing, derived-system-consistency-requires-flush-and-old-values