Sony Bank Taps Fujitsu’s GenAI for Core System Upgrade

Fujitsu Limited and Sony Bank, Inc. have announced the integration of generative AI into the system development of Sony Bank’s new core banking platform, which is built on Fujitsu’s core banking solution, starting from September 2025.

In May 2025, Sony Bank completed a full cloud migration of all its systems through the adoption of a cloud-native core banking system powered by Fujitsu’s technology. This transformation has greatly improved the flexibility, scalability, and operational efficiency of Sony Bank’s infrastructure.

The initiative represents the first step toward building an AI-driven development ecosystem, utilizing generative AI within Sony Bank’s cloud-native framework. Looking ahead, by April 2026, both companies aim to expand generative AI deployment across all core banking system development projects, paving the way for an advanced AI utilization model in Japan’s financial sector.

Tatsuya Fukushima, Corporation Executive Officer, Sony Bank, said

“Our goal is to deliver new value to our customers through technological innovation. We are excited to embark on this collaboration with Fujitsu, integrating generative AI into our core banking system development. This partnership isn’t just about efficiency and quality; it’s about unlocking more flexible and agile services for our customers. Merging our cloud-native environment with cutting-edge AI marks a significant leap forward in redefining the future of financial services.”

Masaru Yagi, Corporate Executive Officer, SEVP, Fujitsu Limited, said,

“Building on the successful delivery of the next-generation digital banking system in May, Fujitsu is proud to partner with Sony Bank on a strategic initiative that will apply generative AI to innovate system development. This undertaking marks the official launch of our vision for a truly AI-driven development ecosystem, centered on generative AI. By integrating Fujitsu’s AI expertise and business knowledge into Sony Bank’s operational core banking solution, we expect to significantly accelerate their development and service delivery.”

Sony Bank and Fujitsu will initially implement generative AI in the development and testing stages of their core banking systems. This collaboration will utilize Fujitsu’s proprietary knowledge graph-enhanced RAG technology, which refines AI input by linking relationships across large datasets to deliver more accurate outputs.

Looking ahead, the partners plan to extend generative AI-driven development consistently across all phases — including management, requirements definition, operations, and maintenance — targeting a 20% reduction in development time.

By executing all processes entirely on AWS, the initiative will deliver greater scalability, enhanced security, and significantly improved development efficiency. Together, these efforts will establish a robust development ecosystem, maximizing the combined strengths of Fujitsu’s core banking solution and AWS integration to ensure continuous quality improvement and faster development cycles.