This course focuses on choosing the right software systems architecture for complex software systems. A proper architecture for a software helps to meet the organizational business goals. The topics include an overview of software systems architecture, architectural patterns, reference models and reference architectures, system quality attributes (availability, scalability, performance, modifiability, security, testability, usability), designing and documenting the system architecture, analyzing architectures, software product lines, and component and service-oriented architectures. A substantial amount of architecture issues will help to choose the suitable architectural pattern for software. That eventually helps to build, maintain and extend the system.