ABSTRACT
As the COVID-19 pandemic spread throughout the United States in Spring 2020, universities around the country conducted the unprecedented feat of moving essentially their entire curricula online. This abrupt mid-semester shift in modality was the first of its kind at scale, but it will not be the last. Now that our experiences during the pandemic have demonstrated that an online transition is possible, we may see similar transitions proposed during smaller scale crises, especially as an alternative to school closures. We present an experience report focusing on computer science instructors at a large Midwestern university during the Spring 2020 online transition: the challenges they faced, as well as the interventions they implemented. As more data and analysis is generated from the first mass, unwilling modality shift, it is nevertheless important to focus on the visceral reactions and lessons learned from teachers and students in the moment as they responded to an unprecedented situation. We therefore also present our analysis of critical challenges and preliminary pedagogical recommendations for consideration during future rapid transition "involuntarily online"semesters. © 2021 ACM.