In the context of Indonesia’s digital transformation, state governance is increasingly mediated by algorithmic systems embedded in the Sistem Pemerintahan Berbasis Elektronik (SPBE) and Satu Data Indonesia (SDI) policies. While these systems aim to enhance administrative efficiency, transparency, and data interoperability, they raise critical concerns regarding constitutional legitimacy and the erosion of popular sovereignty (kedaulatan rakyat) as codified in Article 1(2) of the 1945 Constitution. This study investigates how algorithmic infrastructures displace constitutional actors, reconfigure legal subjectivity, and create normative gaps in democratic accountability. Employing a qualitative methodology that integrates doctrinal legal analysis and interpretive fieldwork, the research draws on key legal texts, international frameworks, and expert interviews with stakeholders from government, academia, and civil society. Thematic coding of interview transcripts revealed six dominant patterns: displacement of constitutional actors, opacity and accountability, automated legitimacy, jurisdictional blind spot, participatory deficit, and posthuman subjectivity. Findings demonstrate that SPBE and SDI are not neutral policy tools but constitutional events that reallocate evaluative authority and legal recognition to automated systems, often without oversight, redress, or public participation. This study introduces the concept of algorithmic constitutionalism, a normative model that positions digital infrastructures as actors in constitutional discourse. It calls for doctrinal innovation to ensure transparency, participatory safeguards, and judicial scrutiny in algorithmic governance. These insights contribute to both Indonesian constitutional theory and the global conversation on digital sovereignty.