After serving in the U.S. Navy and later working as a manager in vaccine research and development, Waldstein joined the Immunology Doctoral Program at the University of Iowa. His main research interest was to understand how mutations in viral proteins induce inflammation and cause severe disease. At the UI, Waldstein also served as a postdoctoral research scientist in Professor Xiaoyang Hua's laboratory. In addition, he served as a member of Graduate Council, while also receiving the Distinguished Student Leader Award in 2022. Waldstein currently serves in the U.S. Army.