In this paper, an Assistive Technology Professional (ATP) and two engineering instructors share how an engineering program and a school that serves students with extensive support needs develop a partnership based on engineering design and the development of assistive technologies. We use a qualitative cross-case analysis approach to understand and share the development of the partnership over three sequential courses, each of which we frame as a case. While there are differences in the cases informed by the time in the partnership they took place, prioritizing front-end design vs. prototyping activities, and different learning outcomes for the courses, some strong themes to understand key aspects that inform the partnership emerge. These themes include building sustainable partnerships of trust, the role of people as connection agents, centering issues of power and justice, and engineering design as a medium to support partnerships.