The transition to online instruction during the COVID-19 pandemic was unprecedented and forced many universities to quickly embrace online distance learning. This context created new challenges, particularly around assessment strategies. Empirical research has demonstrated that formative assessment fosters more active learning in online classrooms. However, formative assessment strategies are not always adapted well to online platforms based on the nature of the subject matter and the size of the class. This qualitative case study sought to understand instructors' experiences and strategies for conducting assessment remotely, specifically for large-size undergraduate courses. The investigation relied on data from semi-structured interviews with University of Maryland, College Park instructors who received a Teaching Innovation Grant from the Provost's Office in Summer 2020 intended to fund sustainable online delivery beyond the emergency response teaching phase. For this analysis, we analyzed the transcripts of 13 interviews, representing a diverse range of programs, schools, and faculty seniority levels at the university. Findings show instructors experienced several successes during course retooling, including significant increases in student performance. Most instructors also indicated that they would continue to keep new online assessment strategies for the future, regardless of whether that future includes online, blended, or in-person delivery. Despite the anticipation that the pandemic would fuel more opportunities for cheating, there was only one experience of academic dishonesty.