Understanding the End-to-End Architecture of Chinese Internet Payments

The article introduces the complete payment chain in China, starting from an e‑commerce platform (e.g., JD.com) where users select products, proceed to the checkout page, and choose among third‑party payment methods such as JD Pay, WeChat Pay, or UnionPay, which then route through commercial banks, the UnionPay/NetUnion networks, and finally reach the People’s Bank of China.

It presents a high‑level diagram of JD’s payment architecture (see image below).

The core components of a typical service‑platform payment system are described: a user‑facing cash register (cashier), an order system that records business transactions, a transaction system that converts business requests into payment orders, a payment system that processes those orders, and a payment‑channel subsystem that communicates with external payment providers.

The payment system is divided into a business layer (handling user‑facing operations such as cashiers, order management, and member services) and a payment layer (real‑time fund settlement, account flow tracking, and fund splitting/merging).

The member system manages user identities within the payment platform, storing personal and enterprise member information, linking accounts, operators, and bank cards, and supporting both individual and merchant members.

The payment core abstracts various payment services (e.g., recharge, withdrawal, internal transfer, refund), defines payment flows, and standardizes payment instructions and protocols to provide a unified interface for front‑end products.

The accounting core handles account types, records fund movements, generates accounting data, and reconciles payment‑channel settlements, while the settlement core maintains clearing and settlement rules to finalize fund distribution.

Finally, the article emphasizes that building a third‑party payment platform involves dozens of subsystems, illustrating the complexity and breadth of modern payment architecture.