Prof. Rubinstein is an applied mathematician. His research has spanned several disciplines, including partial differential equations, asymptotic analysis, hydrodynamics, superconductivity, optics, medicine and more.

Koby served as the chairman of the Technion Department of Mathematics (2009-2012) and as the president of the Israel Mathematical Union (2017-2018).

He received a number of awards including the Landau Prize in Exact Science, the New England and the Seiden awards for scientific excellence, the H. Rich award for innovation, the S. Kaplan award for creative management and the Member for Life award from the Technion Students Association.

In 2009, he was elected Fellow of the AAAS.