In the ongoing journey to modernize transport systems, T-Systems excels in designing and developing digital solutions tailored to the demands of new trains, integrating radio technology with onboard computer software within a complex system environment. We meticulously control and integrate various subcontractors and ensure the harmonious fusion of radio technology with the system components of the new G1-type trains, prioritizing high availability and securing regulatory approvals. Collaborating closely with stakeholders, including the train manufacturer, and system component suppliers, we design robust digital solutions that incorporate cutting-edge hardware and software components. Our implementation includes highly available onboard computers with a fallback concept, rigorous system and integration tests, and unwavering support during test operations. The results are transformative; a stable, modern solution with training and documentation, operational reliability, regulatory approval readiness, efficient spare parts planning, and a holistic approach that positions T-Systems as your comprehensive, one-stop solution provider.