This theoretical study examines the role of users in an infrastructural systems design. We analyzed different perspectives and used theories on infrastructure, long-term factors in infrastructure, and the role of users in infrastructural systems design. By doing this we demonstrated how prototypical design has been used in infrastructural systems design and how the users’ role has been taken into account. This study summarizes infrastructuring modes, purposes, activities, and methods and also offers both theoretical and practical contributions. First, we offer a new view on prototypical design as it is conceptualized for infrastructural systems design. Second, as a practical contribution, this study provides valuable knowledge to end users and domain and information systems practitioners, especially regarding how information systems artefacts can contribute to infrastructural design and vice versa.