Schnell earned his undergraduate degree from Universidad Simon Bolivar, and his D.Phil. from the University of Oxford in 2002, and completed a Wellcome Trust Senior Research Fellowship at that institution.
He was appointed as an assistant professor at Indiana University in 2004 and joined the faculty at U-M in 2008 as an associate professor in the Department of Molecular & Integrative Physiology. In 2013, he was jointly appointed as associate professor in the Department of Computational Medicine and Bioinformatics. He was promoted to professor in both departments in 2015 and was recently named as the John A. Jacquez Collegiate Professor of Physiology.