A Bilingual Livestock Marketplace with Auctions, Wallets & Bank-Connected Payouts

The Challenge

Livestock commerce breaks every assumption of ordinary e-commerce.

An animal is not a SKU on a shelf. A single listing may be sold whole, by head, or split between multiple buyers. The "product" often includes services — slaughtering, a specific cutting method, packaging, delivery — some optional, some required, each priced by quantity. Once an animal is slaughtered, a normal return is impossible, so refund rules must understand fulfilment state.

Buying behaviour is equally non-standard. Some buyers want to purchase instantly; some want to post what they need and let sellers compete; some want to bid privately without revealing their offer to rivals. Sellers range from individual owners to farms and central vendors with managed inventory, working hours and response deadlines.

And underneath it all sits money movement that must behave like fintech: buyer payments by card, bank transfer or wallet; funds held until delivery; commissions calculated across price components without double-charging; refunds routed back to the exact source; and sellers paid out through real banking rails. Every one of these steps can go wrong concurrently — multiple buyers against the same stock, bids expiring on timers, payments arriving while offers lapse.

Engineering for Financial Correctness

Marketplace revenue depends on totals like this being right every single time:

• No double-charging: commission logic was hardened so each price component is charged exactly once — including a fix where packaging briefly attracted a duplicate commission.
• No duplicate payouts: bank-response handling was redesigned so a pending enquiry can never cause a payment instruction to be transmitted twice.
• No phantom successes: card payment callbacks are validated against the gateway before any success screen or crediting occurs.
• No refund misrouting: refunds detect the original payment source and return funds to the initiating buyer — a critical correction after tender refunds once routed toward sellers.
• No race-condition sales: auction acceptance, losing-bid cleanup, stock reservation and timer expiration are coordinated so one animal cannot be sold twice.