Walter Fontana studied biochemistry at the University of Vienna, Austria, where he graduated in theoretical chemistry. He subsequently joined Los Alamos National Laboratory in New Mexico as a postdoctoral fellow and continued postdoctoral work at the nearby Santa Fe Institute. Walter then returned to the University of Vienna, but relinquished tenure to follow a call back to the Santa Fe Institute on a 6-year term-limited appointment. In 1999/2000 he was a member of the Theoretical Biology Program at the Institute for Advanced Study in Princeton. Walter moved to the Department of Systems Biology at Harvard Medical School shortly after its founding in 2004. His research is primarily situated at the confluence of computer science, biology, and chemistry. For a decade he also led an experimental project on aging in C. elegans. In 2019/2020 Walter held the annual chair in Informatics and Numerical Sciences at the Collège de France, Paris.