This thesis is concerned with improving the engineering of auto-scaling policies for cloud based applications through a model-based approach. Throughout this paper I create a graphical editor for the scaling policies introduced by Klinaku et al. [KHB21]. Problem. Working with scaling policies is currently done with a tree-based editor. These can be a problem either for software architects that are used to graphical modeling languages such as UML, for whom a tree editor might make their work more tedious or e.g., for communicating scaling concerns to stakeholders such as financial managers or clients because understanding technical terms via a tree editor can be especially difficult for them. Objective. The objective is to design and implement a graphical editor for scaling policies that makes the creation of policies easier and to improve the understanding of scaling policies as part of the research question of this thesis. Method. To implement the graphical editor, I design a model for it based on state-of-the-art research on visual notations. To refine the model, I gather feedback from three experts of software quality and architectures. I have implemented the graphical editor in Eclipse Sirius. Result. For validation, I perform an evaluation session where participants from the industry and academia have been asked to give feedback via a questionnaire on their experience using the graphical editor. Almost all participants have found the design to be appropriate and two thirds of participants have reported a high value for helpfulness of the graphical editor. Conclusion. Lastly, I summarize key aspects of the thesis, discuss benefits and limitations to the graphical editor and my findings. Additionally, I present the lessons I learned and point out potential future work.