This book provides a comprehensive exploration of artificial intelligence in financial technology, bridging foundational concepts, core architectures, and advanced applications. Part I introduces the evolution of fintech, AI's role in reshaping services, and the regulatory landscape, highlighting compliance, explainability, and global frameworks. Part II delves into enabling technologies, including AI-driven payment infrastructures, microservices, event-driven systems, and secure data engineering tailored to finance. Part III advances into applications such as liquidity optimization with multi-agent systems, AI-enhanced cross-border payments, and next-generation credit scoring that addresses fairness and bias. Part IV presents case studies from banks, fintech startups, and insurers, followed by frameworks for building scalable, secure, and ethical AI systems. Concluding with future directions, the book examines autonomous finance, generative AI, CBDCs, and decentralized models, offering a roadmap for research and innovation.