Pillay is one of the leaders in the environmental sector in South Africa. He obtained his PhD at the Pollution Research Group of the University of KwaZulu-Natal, one of the leading water research centres in the world. He also worked as a consultant for the group carrying out projects for the Water Research Commission and the private sector. He was part of the team that advised the eThekwini Municipality on the provision of free basic water in eThekwini. His work on this subject has been presented at many international conferences including the World Summit on Sustainable Development. He was a pioneer in the use of life cycle assessments in the water industry and was responsible for the development of an environmental performance indicator for water providers. Pillay was a co-author for the 2002 United Nations Environment Programme report on sustainable development in sub-Saharan Africa.

Pillay has worked as a consultant in the mining and metals sector before joining Sasol. In his role as the coal and environmental technology manager at Sasol, he is responsible for the development and introduction of new technologies in this area. He has led the teams responsible for the new water and waste handling systems for new gas-to-liquid, coal-to-liquid and chemicals projects and driven the focus on improving the environmental performance of the current asset base. With the changing environmental landscape, there is a need for greater innovation in this space and Sasol is positioning to respond to these challenges.