Sony Bank and Fujitsu use generative AI to accelerate core banking development

Sony Bank and Fujitsu have successfully integrated generative AI into the development of core banking systems. By utilizing AI agents powered by Anthropic’s ‘Claude’ model via Amazon Bedrock, the companies have established a workflow that spans design, programming, and testing.

As of July 2026, the implementation has demonstrated a 30% reduction in the development period from basic design to integration testing, alongside a 40% reduction in total man-hours. Specific efficiencies include a reduction of up to 90% in the effort required to investigate the impact of changes on other functions and in executing integration tests. The source code generation rate reached 99% during the programming phase.

The system utilizes Fujitsu’s ‘Core Banking xBank’ on AWS, a cloud-native architecture that allows for rapid testing and integration of AI services. While AI handles much of the technical production, human experts remain responsible for final judgment, approval, and quality assurance. Fujitsu plans to expand these findings to other financial institutions using the xBank solution.