This volume presents selected papers from the IV International Workshop on Hybrid Methods of Modeling and Optimization in Complex Systems, focusing on interdisciplinary advances in hybrid modeling, artificial intelligence, optimization, and digital technologies for complex problem solving. The volume explores hybrid optimization techniques, transfer learning, fuzzy systems, cyber-physical systems, AI-driven economic and industrial applications, digital transformation, sustainable development, BIM and digital twins, intelligent forecasting, and decision-support systems. It also covers data mining, machine learning, multimodal analysis, semantic search, financial and medical data processing, as well as domain-specific applications in architecture, environmental engineering, forestry, and industrial systems. Combining theoretical developments with practical implementations, the book demonstrates how hybrid methodologies improve analytical accuracy, system adaptability, and intelligent decision-making across scientific, technological, and economic domains. It is intended for researchers, engineers, practitioners, and graduate students working in complex systems, artificial intelligence, and interdisciplinary modeling.