New technologies, increasing user demands, efficiency pressure, and shifting developer workflows require continuous modernization of IT platforms. In some cases, this requires a complete rethinking from the ground up. For the central financial platform of the Sparkassen Finance Group, transitioning to the next-level enterprise architecture of the future is a monumental task. This undertaking must balance strict regulatory requirements, the continuation of legacy systems, and openness to new technologies, all while focusing on the work reality of 1,700 software developers. In this talk, Maik and JC provide practical insights into the architecture and technology roadmaps and the corresponding change management activities for frontend, backend, and cloud-native environments that drive the modernization of the financial platform, serving 50 million Sparkasse clients.