Researchers regard digital technologies both as conditions to engage active citizens in urban governance and as power devices that deprive most participants from their activity in social interactions. Discussing such problematic activity, we formulate the following research questions: how does digital technology work as means for citizen engagement in governance? How does citizen activity become an element that presupposes a constructive transformation of technologies? The article presents the empiricalstudy of citizens’ participation in urban governance within voting and discussing the “Program for the renovation of the housing stock in Moscow” that involved the usage of the “Active citizen” digital platform. We regard this platform as a part of the digital technology of city governance. The conceptual basis for the research refers to the Science and Technology Studies: we elaborate on the concepts of agency and activity to determine the nature of participation in the governance; and fluidity to describe a technology with a distributed subject that demonstrates flexibility and the ability to transform while maintaining its unity. The article proposes and substantiates the hypothesis that the technology that fits the purposes of involving active citizens in urban governance should demonstrate fluidity at two levels. In contrast to the first, the second level is related to technology’s ability to take into account both agency and activity of actors articulated in their critical attitudes to digital technology. The “Active Citizen” platform’s case study reveals the conditions and challenges of technology transformation to the second fluidity level.