From 2001 to 2004, Schnell was a Junior Research Fellow at Christ Church,
University of Oxford, and a Research Fellow of the
Wellcome Trust at the Centre for Mathematical Biology. In 2004, he joined the faculty at
Indiana University Bloomington as an assistant professor of informatics and associate director of the Biocomplexity Institute. In 2008, Schnell moved to the
University of Michigan, where he was appointed associate professor of molecular and integrative physiology and a Brehm Investigator in the Brehm Center for Diabetes Research. In 2013, he received a joint appointment as associate professor in the Department of Computational Medicine and Bioinformatics, and in 2015 he was promoted to professor in both departments. He was named the John A. Jacquez Collegiate Professor of Physiology in 2016 and served as chair of the Department of Molecular & Integrative Physiology from 2017 to 2021. During his tenure, the department maintained its status as the top-ranked physiology department in the United States based on funding from the National Institutes of Health (NIH). Schnell is a past president of the
Society for Mathematical Biology. During his tenure, the society launched several new awards to recognize contributions across career stages, including the H. D. Landahl Mathematical Biophysics Award for graduate students and postdoctoral researchers, the Leah Edelstein-Keshet Prize for women in mathematical biology, the John Jungck Prize for Excellence in Education, and the SMB Fellows Program. He also contributed to the society’s fundraising efforts, which reportedly led to a significant increase in its endowment. Schnell has also served as Editor-in-Chief of the journal
Mathematical Biosciences and is a member of the Commission on Standards for Reporting Enzymology Data (STRENDA). == Research ==