This book constitutes the proceedings of the 28th International Conference on Web Services, ICWS 2021, held virtually as part of SCF 2021, during December 10-14, 2021. The 7 full papers presented in this volume were carefully reviewed and selected from numerous submissions. The papers cover aspects of services computing and applications. Centered around services computing, it covers various systems and networking research pertaining to cloud, edge and Internet-of-Things (IoT), as well as technologies for intelligent computing, learning, big data and blockchain applications.