Service-Oriented Architectures (SOA) evolved from earlier approaches to distributed computing and modularization, and enterprises have been running information systems that employ SOA as they architectural style for more than a decade. More recently, microservices have been proposed as a lightweight and flexible approach to service development that aligns well with modern software engineering practices such as continuous delivery and DevOps.
In this presentation, we first study why and how general software architecture concepts and SOA principles and patterns were applied during the evolution of two large-scale enterprise application landscapes in the finance and telecommunications industries. Next we review key microservices  tenets and critically discuss their novelty and applicability in different application contexts. Finally, we reflect on architectural decisions recurring in SOA and microservices design, and present emerging tool and middleware support for architectural knowledge management and service decomposition.  

Olaf Zimmermann is a professor and institute partner at the Institute for Software at the University of Applied Sciences (HSR FHO) in Rapperswil, Switzerland. His areas of interest include Web-based application and integration architectures, SOA and cloud design, and architectural knowledge management. Previously, Olaf was a senior principal scientist at ABB Corporate Research and a research staff member and executive IT architect at IBM Research who investigated the role of architectural decisions in the design process. From 1999-2005, Zimmermann worked as a solution architect and consultant, helping international clients in multiple industries build enterprise-scale SOA/Web services and Java Enterprise Edition solutions on professional services projects. In the beginning of his career, he was a scientific consultant and developer in the IBM European Networking Center (ENC) in Heidelberg, Germany, focusing on industry-specific middleware frameworks for systems and network management. Zimmermann is a certified The Open Group Distinguished (Chief/Lead) IT Architect and a member of the editorial board of IEEE Software. He is a regular conference speaker and instructor. He also is an author of Perspectives on Web Services (Springer, 2003) and contributed to several IBM Redbooks, including the first one on Eclipse and Web services (2001).