Algorithmic Caste Enumeration: Constitutional Validity of Digital Census 2027’s GIS-Based Self Count Algorithm

India’s 2027 census marks the first fully digital caste-based enumeration exercise since 1931. The census of 2027 incorporates a new inclusion of Geographic Information System (GIS)-based self-count algorithm to carry out the survey for millions of households through mobile app-based data collection, geographic information system geotagging, and machine learning validation checks under the Census Act, 1948. The use of such a technological system raises various constitutional concerns with regard to the intersection of rights, such as the right to privacy, the right to equality and the governance of algorithms. In this paper, the constitutionality of such an algorithmic architecture is tested against Article 14(equality) and Article 21(privacy) in light of the Supreme Court’s decision in K.S. Puttaswamy v Union of India (2017). By employing the methodology of doctrinal legal analysis, the paper analyses whether the caste enumeration on the basis of GIS could meet the triple test of legality, necessity and proportionality as enunciated by the Puttaswamy judgment. Moreover, the analysis is extended to the extent of whether the location-based caste map is in violation of Article 14’s prohibition against arbitrary classification and Article 15(1)’s prohibitory rule against caste-based discrimination. The paper also provides for a comparative analysis of frameworks such as the Digital Personal Data Protection Act 2023 and the EU General Data Protection Regulation, to identify the lacunas in India’s digital census system. The paper also identifies certain critical constitutional challenges, such as GIS geotagging violating Article 14 through location-based discrimination, and algorithmic self-count mechanisms infringing the informational privacy principle. The paper concludes with certain legislative recommendations, which include establishing the National Digital Census Tribunal, obligatory algorithmic audits, and optout GIS provisions, therefore, allowing the continuation of this system based on algorithmic constitutionalism while addressing its challenges in India’s first digital caste census constitutional framework.