This case is centered on the Chinese online fashion retailer Shein. Created in 2012, Shein quickly grew to become an internationally known brand without physical premises, selling products nearly all over the world. The case presents Shein’s international development, examines how the firm revolutionized fast-fashion models by creating a so-called “ultra-fast fashion” model, and explores the underlying multifaceted reasons for its enormous success. The case also describes the limitations of this model, which may eventually hinder Shein’s future growth. Instructors in international business, strategy, digital transformation, supply chain or marketing may use this case to highlight the challenges facing a global company in a competitive industry which developed a new kind of business model, and strategies to maintain the firm’s success under growing criticism