During the COVID-19 pandemic, online learning became a major alternative to college science, technology, engineering, and mathematics (STEM) courses in postsecondary education. Faculty members, although subject matter experts, often lack pedagogical knowledge and training on how to effectively teach new generations of students online, or incorporate appropriate technologies. Faculty teaching online courses needed a new guiding framework to balance domain goals and emerging technologies. We present grounded design for STEM courses to align domain goals and instructional methods and technologies while reflecting instructors' pedagogical beliefs and addressing cultural and pragmatic issues. It is critical to provide students with aligned STEM learning experience and engagement via defensible theories and research-evidenced pedagogy in online and blended courses while technological, cultural, and pragmatic considerations are also addressed. We suggest grounded design as the conceptual and design framework for designing online and blended courses and discuss the assumptions, approaches, and examples. We provide practical guidelines to apply grounded design to online and blended learning environments and suggest future research. This article can assist both novice and seasoned STEM faculty to connect theory and research to teaching practices and optimise their online and blended courses.