Variations in PaaS delivery models  Chapter 2: Digging Deeper into IaaS and PaaS 21 PaaS comes in different shapes and sizes. If you’re using a  public  cloud-based PaaS, the vendor shoulders the responsibility  of managing the middleware software resources and the overall development and deployment environment. If you  decide to create your own PaaS environment, your organization  is responsible for maintaining the right level of service. A public PaaS environment looks and acts very differently  than your traditional development and deployment platform.  For example A  private  PaaS environment also looks and acts differently  than your traditional development platform. Large enterprises  may implement well-designed patterns and best practices to  achieve efficiency and productivity gains and reduce software  development and deployment costs. Increasingly software developers are becoming strategic partners for the business. To support this strategic role,  development organizations are adopting new business practices including the following: ✓ Because the PaaS is tightly coupled with IaaS services, it offers a consistent way to manage and optimize applications from development to deployment (DevOps). ✓ Middleware and services have no installation and configuration because they’re an integral part of the PaaS platform. ✓ The development and delivery of services lives in the  cloud instead of in a single system. ✓ Resources aren’t delivered as software in PaaS. Instead  the PaaS environment is hosted so the third party  is responsible for uptime performance and software  updates.