As cloud computing becomes increasingly popular among enterprises, organizations and developers, it is time to consider how Software as a Service solutions can be built rapidly and cost effectively. This paper presents the possibility of using a service-based architecture operating within the framework of the public cloud computing model and implementing Software as a Service. It also describes the architecture, implementation and testing of sample applications. The conclusions drawn with respect to related work and the results obtained shed more light on the application of public cloud systems for Software as a Service purposes.