Introduction. The article substantiates the relevance of domestic tourism development, examines the domestic tourist flow dynamics, and pays attention to the importance of mass tourism development for Russian economy. Theoretical analysis. Institutionalization and digitalization are fundamental elements of the mass domestic sustainable tourism development matrix. It is noted that a direct appeal to the tourist services producers by potential tourists through digital institutions becomes a condition for mass tourism restoration of in our country. Empirical analysis. An important role in domestic tourism development is played by the creation of digital products, which include a mobile application-designer of tourist trips “Be your own tour operator”. The paper gives an example of building a tourist route in Samara, proves the advantages of using the services of the proposed application. Results. The formation of mass domestic sustainable tourism requires the production of a customized tourist product, which can be achieved by applying institutional and digital mechanisms to the tourism industry. The customization of the tourist product reduces the role of tour operators in the domestic market and increases the role of tour guides and other direct producers of tourist services, which is the tourism digitalization paradox.