AI cut data warehouse migration cost from $70M to $35M

Westpac says AI-accelerated migration of its legacy St.George data warehouse cut costs from a budgeted $70 million to around $35 million and finished more than two years early, with CEO Anthony Miller citing AI tools for faster code conversion, testing and documentation. The bank expects about $15 million a year in direct benefits, plans to decommission the old warehouse in FY27, and says the project produced a reusable AI data migration capability for other migrations.