Revolving around the AI platform ModelArts and the development process of AI applications, this book introduces fundamental concepts, key modules, and typical application development scenarios. The book is divided into three parts: The first part is an overview of AI application development (Chapters 1 and 2), introducing AI technology, applications, platforms, and the rapid development process of AI applications. The second part details the development methods for AI applications (Chapters 3 to 9), covering the entire process and sub-processes of AI application development. This includes data preparation, algorithm selection and development, model training, model evaluation and optimization, application generation, application assessment and release, and application maintenance. The third part presents practical scenarios for AI application development (Chapters 10 to 12), discussing enterprise-level AI platforms, automated AI systems for complex industries, and AI platforms and application development based on edge cloud collaboration.This book aims to allow every developer to leverage the ModelArts platform for faster, more efficient, and cost-effective development of AI applications in specific business scenarios through a complete set of toolchains and methods so that they can better address the real-life issues facing various industries and fields. This book is suitable as a reference for developers aspiring to engage in AI application development.