Recently we witnessed a deep transformation in the the design, development and management of modern applications, which have grown in scope and size becoming distributed and service-oriented. A big part in this metamorphosis is played by the Cloud with the availability of almost-infinite resources, high availability and outsourced maintenance. This has led to the emergence of new software development methodologies to effectively deal with this paradigm shift in the field of software engineering. DevOps is one of them, it advocates for a greater level of collaboration and convergence between developers and other IT professionals. Consequently, new tools, purposely designed to ease this process, are required. In this scenario, we present SPACE4Cloud, a DevOps integrated environment for model-driven design-time quality of service assessment and optimization, and runtime capacity allocation of Cloud applications.