Following his studies in Moscow Technological University Greg started his career in Russia as a research engineer in metallurgy.

He was then hired in 1979 by East Chicago, Indiana, research laboratory operated by Inland Steel Company which was purchased by Mittal in 1998, becoming part, successively, of Ispat International, Mittal Steel and ArcelorMittal.

He rose progressively to become vice president of research and development (R&D) and technology in 1995. He was then named chief technology officer for Mittal company. After Mittal and Arcelor merged, he became vice president for global R&D of ArcelorMittal in 2007. Greg was appointed executive advisor to the Executive Office, effective 1 January 2025. Greg will report to the Executive Office

Greg holds two dozen patents and is the author of numerous publications in the field of physical metallurgy.

In 2014, Greg received Global Platts Metals’ lifetime achievement award.