Born and raised in Jerusalem, Jonathan Mosheiff was first exposed to computer programming at home, at the age of seven. While in high school, this interest led him to compete as a member of the Israeli team in the International Olympiad in Informatics (IOI). Training for this competition, Jonathan was introduced to algorithms and combinatorics and fell in love with the field. He eventually won four silver medals as a representative of Israel in international competitions. During high school, Jonathan studied toward a BSc in computer science and mathematics at the Hebrew University and graduated magna cum laude. He then served for five years in the IDF as an algorithmic researcher and team leader. After the army, he went on to study for an MSc in computer science at the Hebrew University. His MSc thesis, under the supervision of Prof. Orna Kupferman, dealt with the decomposition of regular languages, a theoretical subject with possible applications in the field of formal verification. He was awarded his degree summa cum laude.

After finishing his MSc, Jonathan began working toward a PhD under the supervision of Prof. Nati Linial. His current research, in the field of Graph Theory, deals with local profiles of graphs. The graph, an important mathematical structure representing a binary relation on a set of objects, is relevant to many different areas of mathematics and computer science. For example, a graph can be used to describe all the friendships within a group of people. Jonathan's research concerns properties of graphs that can be determined even if we are given only information about a part of the substructure of the graph, and not the graph itself.

In addition to his research, Jonathan coaches the Israeli team for the International Olympiad in Informatics – the same team in which he was once a contestant. He also created an algorithmic problem-solving course at the Hebrew University, which he teaches together with a fellow PhD student.