The increasing relevance of technology and its impact on our everyday life requires multi- and trans-disciplinary studies in order to investigate the ways in which the Information and Communication Technology (ICT) tools are affected by users’ features and by the external environment. In order to enrich existing contributions on this topic, the paper focuses its attention on the city as example of service systems, in order to investigate dimensions and dynamics that influence the city employees’ evaluation and satisfaction in the use of ICT platforms. By adopting the interpretative lens offered by Service Science and Systems Thinking, the domain of city as a service system is analysed and some hypotheses are formulated with reference to the relationships between environment, users, and ICT platform. The hypotheses are investigated through a questionnaire survey on a sample of 1032 municipalities in the Czech Republic and the results are tested using Structural Equation Modelling. The research shows that users’ features and external environment affect the evaluation and the satisfaction of city stakeholders about the use of ICT platforms by underlining the need for enlarging the study on informatics tools, in order to also include subjective variables. The findings are discussed from both theoretical and practical points of view.