Research on the growth of entrepreneurial ventures has proliferated over the last two decades. Unfortunately, existing research work lacks integration, pays insufficient attention to connection with theory and should be more longitudinal. Configurational approach and process research hold considerable promises in order to move beyond these limitations. The objectives of this paper are, on the one hand, to propose one typology of strategic configurations and one typology of growth patterns, both based on configuration and process theories, in order to explain the development of entrepreneurial ventures over time and, on the other hand, to clarify how and why Entrepreneurial IT Service Firms (EISF) change or do not change business model over time and grow accordingly. EISF have been chosen because they represent a well defined sample that deals with one clear-cut growth strategy question, i.e. to focus on services delivery or to move towards a software business model.