Case study-based learning has been successfully integrated into various courses, including software engineering education. In the context of software design courses, the use of case studies often entails sharing of real successful or failed software development. Using examples of real-world case studies allows educators to reinforce the applicability and usefulness of fundamental design concepts, relate the importance of evaluating design trade-offs with respect to stakeholders' requirements, and highlight the importance of upfront design where students that lack industrial experience tend to overlook. However, the use of real-world case studies is not straightforward because 1.) there is a lack of open source repositories for real software design case studies and 2.) even if case studies are available, they are often reported without a standardized format, which may hinder the alignment between the case and the desired learning outcomes. To address the lack of software design case studies for educational purposes, we propose the idea of Open Design Case Study, a repository to crowdsource, curate, and recruit other educators to contribute case studies for teaching software design courses. The platform will also allow educators and students to share, brainstorm, and discuss design solutions based on case studies shared publicly on the repository.