Cloud Computing involves typically provisioning of virtualized and often dynamically scalable resources for IT services operating. Study of developed Cloud platforms shows that they present limitation related to deployment and running of service-based applications that are built from heterogeneous services (programming languages, communication protocols and/or hosting frameworks). In this paper, we present CloudServ, a Platform as-a-Service (PaaS), that is dedicated to service-based applications. Its model extends the Open Cloud Computing Interface (OCCI) specification that is mainly dedicated to IaaS resources. In CloudServ, PaaS resources are continuously provisioned along with the arrival of deployment requests of service-based applications. Experiments of CloudServ demonstrate its good behaviour and highlights its scalability for a huge number of deployed services in Cloud context comparing to classical Cloud platforms.