With the rapid development of cloud computing and digital transformation, well-designed cloud-based architecture is always in urgent need. Illustrated by project cases from the Chinese technology company Alibaba, this book elaborates how to design a cloud-based application system and build them on the cloud. Cloud computing is far from being just a resource provider; it offers database, storage and container services that can help to leverage key advantages for business growth. Based on this notion, authors from the Alibaba Cloud Global Technology Services introduce new concepts and cutting-edge technology in the field, including cloud-native, high-availability and disaster tolerance design on cloud, business middle office, data middle office, and enterprise digital transformation. Resting upon Alibaba's years of practice and achievements in the field of cloud technology, the volume also elucidates the methodology and practice solutions of digital construction, including methodology, product tools, technical processes, architecture design, cloud application capacity assessment and optimization, etc. The book will appeal to researchers, students, and especially IT practitioners, professionals, and managers interested in cloud computing, digital transformation, cloud migration, business middle office, data middle office, as well as the Alibaba Cloud itself.