Software architecture aims to satisfy the software requirements from different points of view. It is represented by models which are the reference for understanding the structure and behavior of the software. In this way, one of the biggest challenges is to ensure that a software system can improve its performance through the use of scalability tactics, especially to support larger number of concurrent users. This paper presents a model-driven deployment approach to design models of distributed software architectures. In particular, models for web-based software systems in order to support its automatic implementation and its dynamic deployment on a cloud computing platform, using the horizontal scaling tactic. In addition, we design and propose Sarch to build the models, a domain-specific language based on the specification of a set of architectural styles and its representation as architectural views.