General Background The rapid advancement of information technology drives the global banking industry to undergo digital transformation to align with policy directives and meet increasingly digital-oriented customer demands. Specific Background Bank BJB Bandung, a major Indonesian regional development bank, has executed a strategic digital transformation by integrating all electronic banking services into the DIGI mobile platform across Android and iOS operating systems. Knowledge Gap However, empirical literature presents mixed findings regarding the impact of digital transformation on banking service quality, while qualitative evaluations of single-platform integration in regional banking operational contexts remain understudied. Aims This study investigates the practical operational implementation of the DIGI application at Bank BJB Bandung and evaluates its direct influence on multidimensional service quality. Results Utilizing a qualitative descriptive approach with structured observation, bank practitioner key informant insights, and source-technique triangulation, findings demonstrate that DIGI systematically enhances service efficiency, 24/7 accessibility, and multi-layered transaction security. Novelty This research highlights how hybrid banking models successfully synthesize legacy system features—such as bjb SMS—into a unified smart mobile ecosystem featuring advanced digital onboarding (E-KYC), voice text commands, and tailored services like civil servant loan disbursements. Implications A planned, structured digital transformation substantially elevates service quality dimensions and reinforces long-term customer trust in modern banking operations. Key Findings Highlights : Systematic marketing analytics capability serves as the foundational data infrastructure for understanding consumer needs. Verified brand trust functions as the vital mediating driver converting initial brand image interest into repeat purchases. Synchronized management of consumer data and quality consistency maximizes long-term buyer retention in food companies. Keywords : Digital transformation, DIGI Application, Service Quality, Mobile Banking, Bank Bjb