Checkout saga
The orchestration pattern used by checkout to coordinate inventory reservation, payment authorization and order creation.
Checkout SagaCheckout SagaFlowv1.0.0How the Checkout Orchestrator turns a checked-out cart into an order — reserving inventory, authorizing payment and crea...Ownerordering-platformView flowView docs is the detailed orchestration inside Checkout SystemCheckout SystemSystemv1.0.0Internal system that orchestrates checkout. When a cart is checked out it reserves inventory, authorizes payment, and as...Ownerordering-platformMapView docs. It exists because checkout cannot be a single local transaction: inventory, payment and order state are owned by different systems.
Flow map
Saga steps
| Step | Contract | Owner |
|---|---|---|
| Reserve inventory | Reserve InventoryReserve InventoryCommandv1.0.0Command to reserve stock for the items in a checked-out cart. Ownerordering-platformSchemaMapView docs | Inventory SystemInventory SystemSystemv1.0.0Internal system that tracks stock and reserves it for orders. It is the source of truth for available inventory and conf...Ownerfulfilment-platformMapView docs |
| Authorize payment | Authorize PaymentAuthorize PaymentCommandv1.0.0Command to authorize payment for the total of a checked-out cart. Ownerordering-platformSchemaMapView docs | Payment Processing SystemPayment Processing SystemSystemv1.0.0Internal system that orchestrates payment for orders. It authorizes payments, requests charges from the external payment...Ownerpayments-platformMapView docs |
| Create order | Create OrderCreate OrderCommandv1.0.0Command to create a new order from a checked-out cart. Ownerordering-platformSchemaMapView docs | Order Management SystemOrder Management SystemSystemv1.0.0Internal system that is the source of truth for orders. It creates orders, tracks their lifecycle, and publishes events ...Ownerordering-platformMapView docs |
Success condition
Checkout succeeds only when inventory is reserved, payment is authorized and an order is created. The durable outcome is an order in Order DatabaseOrder DatabaseContainerv1.0.0
PostgreSQL database that is the system of record for orders and their items.MapView docs and subsequent Order CreatedOrder CreatedEventv1.0.0Published when a new order has been created.
Ownerordering-platformSchemaMapView docs publication.
Compensation
If inventory is unavailable or payment is declined, checkout should not create an order. The orchestrator should release any previous reservation or void any authorization as needed.
Change guidance
Adding a checkout step means updating:
- the flow definition,
- the orchestrator implementation,
- the command/event contracts,
- failure and compensation behavior,
- customer-facing status semantics.
Review this checkout saga change as a senior distributed systems engineer. Check whether every step has a clear owner,
success condition, failure condition, retry policy, compensation action and customer-visible status. Call out any
missing contracts or catalog pages that should be updated before release.Review this checkout saga change as a senior distributed systems engineer. Check whether every step has a clear owner, success condition, failure condition, retry policy, compensation action and customer-visible status. Call out any missing contracts or catalog pages that should be updated before release.