This book constitutes the refereed proceedings of the 15th Symposium and Summer School on Service-Oriented Computing, SummerSOC 2021, held in September 2021. Due to the COVID-19 pandemic the conference was held online.
The 9 full and 2 short papers were carefully reviewed and selected from 24 submissions. The papers are organized in topical secions on ?quantum computing; advanced application architecture; service-based applications.