The Fourth Edition of the Software Architecture: Theory, Technology, and Applications (SA-TTA 2016) is part of the 31th ACM/SIGAPP Symposium on Applied Computing (SAC).  For the past thirty years, ACM SAC has been a primary gathering forum for applied computer scientists, computer engineers, software engineers, and application developers from around the world. SAC 2016 is sponsored by the ACM Special Interest Group on Applied Computing (SIGAPP), and will be held in Pisa (Italy), hosted by the University of Pisa and Scuola Superiore Sant’Anna University.