Аннотация: (English) The article discusses the theoretical foundations of multi-user architecture and its practical implementation, using the DraftKings platform as an example. It analyzes three basic tenant isolation models and key patterns for organizing data storage in multi-user systems. It pays special attention to the problem of traffic isolation and financial transactions in conditions of high workload and regulatory restrictions. The article shows how the DraftKings architecture combines scalability, resilience, and compliance through the use of microservice approach, AWS infrastructure, proprietary testing, and risk management solutions. It highlights organizational and technical measures to reduce financial, regulatory, and reputational risks. Promising directions for the development of multi-user architectures are also noted.