Information Systems Quality (ISQ) is a critical source of competitive advantages for organizations. In a scenario of increasing competition on digital services, ISQ is a competitive differentiation asset. In this regard, managing, maintaining, and evolving IT infrastructures have become a primary concern of organizations. Thus, a technical perspective on ISQ provides useful guidance to meet current challenges. The financial sector is paradigmatic, since it is a traditional business, with highly complex business-critical legacy systems, facing a tremendous change due to market and regulation drivers. We carried out a Mixed-Methods study, performing a Delphi-like study on the financial sector. We developed a specific research framework to pursue this vertical study. Data were collected in four phases starting with a high-level randomly stratified panel of 13 senior managers and then a target panel of 124 carefully selected and well-informed domain experts. We have identified and dealt with several quality factors; they were discussed in a comprehensive model inspired by the ISO 25010, 42010, and 12207 standards, corresponding to software quality, software architecture, and software process, respectively. Our results suggest that the relationship among quality, architecture, and process is a valuable technical perspective to explain the quality of an information system. Thus, we introduce and illustrate a novel meta-model, named SQuAP (Software Quality, Architecture, Process), which is intended to give a comprehensive picture of ISQ by abstracting and connecting detailed individual ISO models.