Unveiling digital public services: a citizen-led hybrid approach with mystery shoppers and fsQCA

• Citizen-led mystery shopping + fsQCA offers a new lens on digital service quality • Security & reliability are baseline necessities for trust and meeting expectations • User satisfaction needs a richer mix: reliability, security, empathy, clear design • Insights guide admins to balance technical safeguards with empathy and responsive UX This study presents an innovative, rigorous framework to evaluate user satisfaction and expectation fulfilment in digital public services, using fuzzy set Qualitative Comparative Analysis (fsQCA). The study used an empirical dataset from a real digital administrative procedure to integrate the SERVQUAL model’s dimensions with user-specific expectations. The aim was to construct composite outcomes that reflected nuanced perceptions of service quality. The methodological design applied robust calibration thresholds to reflect theoretical guidance and the empirical distribution of scores. This clarifies the link between calibration choices and the complexity of user journeys in digital services. Data were gathered through a mystery shopper exercise in which trained citizens interacted, capturing authentic service encounters. Empirically, high expectation fulfilment emerges when a security baseline combines with reliable execution and responsive handling, while high satisfaction requires security and reliability together with interface clarity and, in some pathways, empathetic support. Taken together, these results emphasising the interplay of technical, procedural, and relational factors. These findings offer actionable insights for public administrators to design user-centred digital services and establish a replicable methodological template for evaluating service quality across diverse contexts. The study also discusses limitations, such as the small sample size, and proposes future research directions, including cross-contextual comparisons, to expand the understanding of digital service quality.