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

Preface

The best time to plant a tree was ten years ago; the next best time is now.

Overall Architecture of Chinese Internet Payments

This article walks through the entire payment chain from point to point, end to end, using the example of buying "Three Squirrels" nuts on JD.com to illustrate the macro‑level flow of internet payments in China.

First, the user selects a product on an e‑commerce platform (e.g., JD.com).

After choosing the item, the user proceeds to the checkout page, which may present multiple third‑party payment options such as JD Pay, WeChat Pay, Cloud QuickPass, etc.

These payment options connect to commercial bank payment channels, which in turn route through the national clearing networks UnionPay and NetUnion.

Finally, the transaction reaches the People’s Bank of China, the ultimate authority in the payment chain.

JD.com Payment Architecture

The payment chain traverses many subsystems, each with a specific responsibility.

Payment Architecture Breakdown

A typical service‑platform payment architecture consists of:

Cashier (front‑end checkout page)

Order system (records business orders)

Transaction system (drives the trade flow)

Payment system (processes payment instructions)

Payment channel subsystem (transmits instructions to banks)

After a payment succeeds, a clearing line processes the data: the transaction is sent to a clearing center for settlement, then to an accounting system for bookkeeping, followed by notifications to the core accounting module and finally to the fund platform for merchant settlement.

Payment System Architecture

The payment system is divided into a business layer and a payment layer. The business layer provides a unified payment interface for downstream services, while the payment layer handles real‑time fund flow, recording, splitting, and merging according to predefined rules.

Business layer: offers payment and receipt interfaces to business systems.

Payment layer: interacts with payment channels to complete fund transfers.

Cashier

The cashier is the user‑facing page where payment channels are selected. It standardizes the checkout experience across devices and supports both payment (e.g., buying a product) and recharge (e.g., topping up a wallet) scenarios.

Transaction Core

The transaction system sits outside the payment core, translating business‑level orders into payment‑system‑recognizable payment orders. For example, in an escrow transaction, the system records payment success and later confirms receipt before releasing funds to the merchant.

Membership System

The membership system manages the identities of all participants in the payment platform, maintaining a unified member profile (personal or enterprise) and linking accounts, operators, and bank cards.

Payment Core

The payment core provides unified services such as payment, refund, withdrawal, and internal transfer, defines payment instructions and protocols, and abstracts the underlying payment channels.

Accounting Core

The accounting core creates and manages account types, records fund movements, and generates accounting data that aligns with corporate financial standards, reconciling with payment‑channel settlements.

Clearing Core

The clearing core maintains clearing and settlement rules, executing fund distribution and settlement according to configured policies.

Conclusion

Building a third‑party payment platform involves dozens of subsystems; the architecture is far from simple.

Author: Liu Mai Shen Jian

Source: juejin.cn/post/7101522332883091463