Commonwealth Bank undertakes major data migration to the cloud
The Overview
The Commonwealth Bank of Australia (CBA) is headquartered in Sydney, Australia. It has a strong presence in retail, commercial and institutional banking. As one of the largest banks in Australia, CBA serves approx. 16 million customers. The bank focuses on providing retail and commercial banking services predominantly in Australia, and in New Zealand through its subsidiary, ASB.
RFI Global recognises CBA’s digital excellence, naming it the “Most Innovative Major Consumer Bank” and “Best Digital Consumer Bank (Major)” for seven consecutive years.
In May 2025, CBA successfully executed migrations to Amazon Web Services (AWS) in the southern hemisphere, spanning over 10 petabytes of data and 61,000+ jobs sourcing data from 200+ source systems.
The Challenge
12+ years of on-prem data platform legacy, with immense data complexity and intricate inter-dependencies, limited AI readiness.
CBA’s aging data platforms restricted scalability, agility and innovation with growth of 300TB in data per month, ~49K daily job runs, and over 8,000 files.
These legacy systems were no longer suited to advanced AI/ML workloads or federated data product models.
The Objective
Modernise infrastructure, enable AI leadership and accelerate innovation.
Key points included:
- Modernise legacy infrastructure by migrating from on-premises platform to a scalable, cloud-native architecture on AWS
- Enable the potential of AI with the aim of positioning CBA as a leader in AI adoption, leveraging cloud-scale data and advanced analytics
- Enable the build of a federated data ecosystem through a group data marketplace, supporting a producer–consumer model and enabling self-service access to operational and analytical data
- Enable greater velocity and autonomy for delivery teams
The Solution
Accelerated Cloud migration
Before beginning the scale migration, HCLTech supported CBA in building core capabilities, ensuring a strong foundation.
Key elements for accelerated scale migration included:
- Collaboration across CBA, HCLTech and AWS
- Build accelerator tools and lift and shift data to S3 and jobs to EMR with minimal changes
- Drive automation, adopting team topologies and a squad-based model that enabled the successful completion of the scale migration within 9 months
The Impact
Measurable results and qualitative improvements
Migration scale
- 61,000+ jobs, 10+ petabytes of data to AWS — the largest and fastest migration to AWS in the southern hemisphere
Talent transformation
- Upskilled over 300 data engineers
- Elite engineers (AI engineers) embedded into migration teams
Operational velocity
- Delivered four releases and 10 sprints
- High acceleration in program delivery without compromising data integrity or system performance
- Migration completed without any material business impacts
