State machines
Entity lifecycles and state machines that drive the platform.
The business logic, grouped by bounded context. Each entity has a state machine that owns its allowed transitions — the diagrams here are the source of truth.
Inventory
What sellers list. Listings cover the listing lifecycle (draft → available → reserved → sold). Offers handle buyer-initiated negotiation.
Transactions
How money and goods move. Orders own the five-region business model (order, payment, fulfillment, payout, dispute). Fulfillment tracks label purchase and delivery state. Payouts settle seller earnings. Disputes are the dispute region of the order machine: how a conflict is triaged, decided and settled.
Users
How accounts come into being. Onboarding covers the buyer and seller eligibility flows.
Automations
Long-running flows the system drives. WhatsApp bot handles listing creation via chat. The Queen is the full end-to-end test that exercises every state machine.