How CMB Completed a Full Cloud Migration and What Banks Can Learn

On February 27, the "Overall Layout Plan for Digital China Construction" was issued, calling for deep integration of the digital and real economies and accelerating digital technology innovation in key sectors such as finance.

China Merchants Bank (CMB) is accelerating its digital transformation to align with the Digital China initiative. By leveraging its fintech strengths, CMB links its financial services with enterprise digital transformation needs, addressing customers' pain points and promoting deep digital‑real integration.

In December 2022, CMB completed its three‑year “full cloud” migration, moving the last batch of accounts to the cloud and upgrading its digital foundation. Following five development paths—online, data‑driven, intelligent, platform‑based, and ecosystem‑oriented—the bank has built a solid base for serving both industrial digitalization and digital industry.

Cloud is the core of CMB’s digital strategy. Since early 2020, the bank launched the “full cloud” project, finishing migration of all business systems and customer data by the end of 2022, entering the “cloud era”.

After migration, business innovation accelerated. The open, shared cloud model broke down silos of traditional mainframe architectures, enabling micro‑service reconstruction, rapid assembly of new services, and fast iteration. A “cloud + mid‑platform” architecture, including enterprise‑level technology and data middle platforms, unlocked production capacity for new financial scenarios such as fintech, scenario‑driven services, and operational automation.

Resource provisioning became more flexible. High‑concurrency events like “Double‑11” sales can now be supported by elastic cloud resources that scale horizontally with demand, ensuring smooth execution.

The bank’s CIO emphasizes that cloud provides massive, low‑cost, shared compute resources for big data, AI, and digital applications, while also delivering a business model where financial services are as readily available as tap water, lowering entry barriers for enterprises and individuals.

Technical details of the migration include building a self‑developed cloud platform with a “dual‑path” approach: a “financial transaction cloud” replaces legacy mainframes for high‑throughput trading, and a “native cloud platform” transforms traditional IT into native cloud services. The platform runs both x86 and ARM stacks, supported by a proprietary cloud‑management system and operations tools, achieving 99.999 % availability.

Developers rewrote 2.35 billion lines of code to create a fully micro‑service‑oriented bank, enabling parallel development across business lines and eliminating vertical system silos. Data migration was performed without service interruption, moving billions of records in 503 batches over ten months, ensuring zero impact on customers.

The completed cloud foundation positions CMB to continue advancing digital banking, support the national Digital China agenda, and deliver innovative fintech products and services.