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Gold1410

System Design

Shipping and Fulfillment

Routing orders to warehouses and carriers to get goods to the door.

5 min read · core · beat Gold to climb

From order to doorstep

Fulfillment is the physical process of getting an order to the shopper: picking items, packing them, and handing them to a carrier. The software side coordinates which warehouse ships and which carrier delivers.

Warehouse selection

When stock lives in multiple warehouses, the system picks one using rules such as:

  • Nearest to the shopper to cut delivery time and cost.
  • Stock availability so the chosen site can ship the whole order.
  • Split shipments when no single warehouse has everything.

Carrier integration

The system requests a shipping label and rate from a carrier, then tracks the shipment. Carrier updates arrive as tracking events that move the order through shipped and delivered states.

Reliability

Label creation can fail or time out, so requests must be idempotent and retried. Tracking events should be processed even if they arrive out of order.

Key idea

Fulfillment selects a warehouse, packs, and hands off to a carrier, using idempotent label requests and tracking events to drive order state.

Check yourself

Answer to earn rating on the learn ladder.

1. Why might an order become a split shipment?

2. Why should carrier label requests be idempotent?