The article focuses on the socio-economic significance of the category of public debt. The aim of the article is to develop recommendations on the optimal parameters of public debt, allowing the creation of a mechanism that increases the effectiveness of this financial instrument. By using debt obligations, the state becomes a real participant in the movement of loan capital on the capital market. It is found that without a clear purpose for the financial resources borrowed, public debt can have the opposite effect, depriving the state of its status as a sovereign borrower of financial resources on the financial market. The study substantiates the role of public debt in economic development and the implementation of a digitalization programe, both in the production process itself and in the organization and management of production. It is established that investing in the economy implies the focus on attracting real investments regarding the nature of investment, direct investments according to the participation in investments and the duration of long-term investments. Systematic economic development, based on the comprehensive use of public financial instruments, will provide the country's regions with their own financial resources to form a development budget. The existence of these conditions increases the financial stability and investment attractiveness of the country. It is proven that the effect of public debt is minimal if the fiscal and, consequently, economic policies pursued by the state are ineffective.