This book examines the use of artificial intelligence in design and digital prototyping across different scales, from products and objects to buildings and urban environments. It reviews current AI models applied in design, discusses the use of generative approaches such as diffusion models and GANs, and considers the role of platforms and ecosystems in supporting these processes. Drawing on examples across small, medium, and large scales, it outlines a methodological framework that connects AI-based generation with digital prototyping, offering a structured overview for researchers and practitioners interested in computational design.