- Chair Senior Professor of Chemistry, Department of Chemistry, University of Colombo, Sri Lanka (Jan 2021 – to date)
- Head of the Department, Department of Chemistry, University of Colombo, Sri Lanka (August 2020 – to date)
- Senior Professor in Chemistry, Department of Chemistry, University of Colombo, Sri Lanka (Feb 2013 – December 2020)
- Professor in Chemistry, Department of Chemistry, University of Colombo, Sri Lanka. (Feb 2005 – Jan 2013) (Directly promoted to full Professor from Senior Lecturer Grade II just after 6 years from the PhD and became the youngest Professor (Age 39) in the Faculty of Science, University of Colombo)
- Science Team Leader, Sri Lanka Institute of Nanotechnology (SLINTEC), Nanotechnology and Science Park, Mahenwatta, Pitipana, Homagama, Sri Lanka. (May 2012 – April 2019)
- Research and Development Consultant, Haycarb PLC, Sri Lanka, 2009.
- Research and Development Consultant, Global Rubber Industries, Sri Lanka (2017 – 2019)
- Visiting Consultant, Department of Chemistry, Sultan Qaboos University, Sultanate of Oman. (September 2011 to January 2012)
- Senior Lecturer II, Department of Chemistry, University of Colombo, Sri Lanka. (Oct 1998 – Feb 2005).
- Director, Career Guidance Unit, University of Colombo, Sri Lanka (July 2003 – March 2005)
- Director, Graduate Foundation, University of Colombo, Sri Lanka (November 2003 – March 2005)
- Visiting Lecturer, American National College (ANC), Colombo (Adjunct Faculty Member – Patten University, California, USA), 2004 – to date.
- Visiting Lecturer, Monash College affiliated to Monash University, American National College, 2007 – 2010.
- Lecturer, Department of Chemistry, University of Colombo, Sri Lanka. (1993 – 1998), Promoted to Senior Lecturer after the Ph.D. (Study leave during 1994 – 1998).
- Visiting Lecturer, University of Kelaniya, Sri Lanka. (2001 – 2003).
- Visiting Lecturer, University of Sri Jayawardhanpura, Sri Lanka. (2000-2001 ).
- Visiting Lecturer, Institute of Chemistry, Sri Lanka (2000 – 2003 )
- Supervisor, Department of Chemistry, University of Cambridge, UK. (1997 – 1998).
- Demonstrator, Department of Chemistry, University of Cambridge, UK. (1994 – 1998).
- Assistant Lecturer, Department of Chemistry, University of Colombo, Sri Lanka. 1992-1993.
- Teaching Assistant, Institute of Chemistry, Sri Lanka. 1992-1994
- Management Trainee, Lanka Polythene Industry, Sri Lanka. 1987-1990
