General Background Rapid expansion in digital financial services drives commercial and regional development banks to accelerate technological investments to remain competitive. Specific Background Bank BJB Bandung Branch, a prominent regional bank in Indonesia, implements a digital ecosystem led by the DIGI Mobile platform to transition branch roles toward problem-solving and customer acquisition. Knowledge Gap However, empirical research exploring qualitative frontline perspectives on digital banking implementation and customer satisfaction within the unique institutional context of regional development banks remains limited. Aims This study investigates how digital banking implementation affects customer satisfaction, identifies key satisfaction determinants using an extended Technology Acceptance Model (TAM), and formulates field data-based strategic recommendations. Results Applying a qualitative descriptive single-case study approach via semi-structured interviews with operational staff, direct observation, and secondary data triangulation, findings reveal that perceived ease of use and perceived usefulness dominate customer satisfaction, while peak-hour system stability and onboarding barriers present critical vulnerabilities. Novelty This research highlights the pivotal role of transactional transparency, proactive digital security communication, and human customer support as vital mediating layers between technological capabilities and long-term user trust. Implications Strategic adherence to continuous security guidance, peak-load capacity optimization, and structured digital onboarding significantly enhances customer retention, digital literacy, and service delivery across regional banking institutions. Keywords : Digitalization, Customer Satisfaction, Mobile Banking, Regional Banks, Technology Acceptance Key Findings Highlights Perceived ease of use and perceived usefulness serve as the primary drivers of digital service adoption and satisfaction. Initial digital onboarding remains constrained by mandatory physical ATM activation requirements. System stability during peak transaction periods constitutes the most critical vulnerability for customer experiences.