How China Postal Savings Bank Built a High‑Performance Cloud‑Native Core Banking System

Project Background – China Postal Savings Bank (Postbank) launched a new generation personal‑business core system in 2019 to replace its legacy platform, which could no longer handle the rapid growth of online payments and retail banking. The legacy system processed over 20‑30% annual transaction growth and faced scalability, reliability, and development bottlenecks.

Construction Goals – The bank set four objectives: “new, agile, strong, stable.” It aimed for a new technology stack (a “thin core”), agile development with rapid iteration, strong reliability and risk control, and stable operation using a distributed micro‑service architecture that supports >55 k TPS, meets Level‑4 security, and provides elastic scaling.

Architecture & Path – A dual‑track approach combined deep fintech trend analysis with a “short‑fast‑quick” construction model. The technical route adopted a distributed, unit‑based architecture built on a cloud‑native platform that offers automatic fault detection, strong consistency across multiple data centers, and resilience to hardware or network failures. Business modeling followed a “decouple‑reconstruct‑reuse” methodology, extracting product variables and creating reusable enterprise‑level process, product, and entity models.

Database Selection – To satisfy security and controllability requirements, Postbank evaluated several options and chose the open‑source openGauss database. Extensive testing confirmed its performance (up to 30% higher throughput on X86 servers, 2.01% on Kunpeng), stability (eliminating transaction ID wrap‑around issues), multi‑engine support (row/column/memory), and advanced self‑diagnosis (WDRSnap reports). OpenGauss also aligns with national autonomous‑control policies via the permissive Mulan license.

Deployment Practice – The project spanned 2019‑2022, involving thousands of staff across business and technology units. Key milestones included: March 2019 project kickoff; August 2019 completion of business modeling and distributed‑technology validation; February 2020 full‑scale construction start; April 2021 production of the distributed technology platform; July 2021 launch of the distributed operations platform; November 2021 international remittance module go‑live; April 2022 full production rollout of the new core system; and November 2022 completion of online migration for all 650 million customers using an “online migration, seamless switch” approach that kept both old and new systems running concurrently.

Results & Impact – Since go‑live, the system handles a peak of 67 000 TPS, reduces transaction latency from 95 ms to 65 ms (30% improvement), cuts end‑of‑day processing from 273 min to 197 min (28% reduction), and shrinks quarterly settlement time from 140 min to 25 min (82% reduction). The architecture also provides a reusable foundation for Postbank’s corporate, credit‑card, and loan core systems, accelerating the bank’s transformation toward a high‑efficiency, low‑cost, intelligent digital banking model and contributing to national strategic goals of autonomous, secure core‑banking technology.