Based on the integration of the institutional-structural approach, the resource-dynamic concept, and value-oriented management, it is shown that sustainability is determined not by individual practices (accounting, planning, and hedging), but by the coordination regime between them. The paper describes the architecture of the financial mechanism, which includes four loops: planning and analytical (scenario and stress testing, cash cycle management), accounting and reporting (consolidation of management and financial accounting, ensuring “information truth”), instrumental (diversification of funding sources, factoring, leasing, and derivatives), and risk and compliance (limitation, reservation, covenants, and ERM). It is shown that sanctions have accelerated the restructuring of the mechanism towards funding autonomy, predictive liquidity, and contractual flexibility: internal sources of capital have been expanded, stress-testing practices have been strengthened, covenants have been revised, and hybrid settlement schemes have been introduced. The practical effect is expressed in the extension of liquidity, reduction of currency and interest vulnerability, increase in the turnover of working capital, and stabilization of covenant metrics. The scientific novelty lies in the conceptualization of financial sustainability as a controlled process of aligning the contours of the mechanism with exogenous constraints.