Marcelo studied Mathematics at the Universidad de la Republica in Uruguay and then at Cornell University in Ithaca. He was fortunate to be mentored by great people such as Walter Ferrer-Santos, Steve Chase, and Andre Joyal. Other influential people have been Lou Billera, Ken Brown, Persi Diaconis and Gian-Carlo Rota. He taught at Texas A&M University and is now a full professor at Cornell University. He regards his prior and ongoing monographs with Swapneel Mahajan as his most valuable contributions to the field.
His research interests include topics in noncommutative algebra, category theory and algebraic combinatorics, with Hopf algebras and their generalizations appearing prominently. A goal of his past work has been to build a conceptual framework for the study of Hopf algebraic structures in combinatorics and to clarify its significance to concrete applications. Part of his current work is devoted to enlarging the scope of classical Hopf-Lie theory. The new theory includes hyperplane arrangements and idempotent semigroups as part of the fundamental data. He is developing it in joint work with his colleague and friend Swapneel Mahajan.