HSDS graduated from the University of Ceylon with a first class Chemistry (Honours) degree in 1974. He then continued his education at the University of Southern California, where he obtained his PhD in Chemistry in 1979. He had also completed Parts I, II, and III of the Chartered Institute of Management Accountants. He started his professional career at Grindlays Bank as an Executive in 1980, and then moved to DFCC as a Management Consultant in 1982. Then in 1983 HSDS started his career in Leasing at Mercantile Leasing Limited, which company he help set up and retired as the Deputy Managing Director in 2000. From 2000 to 2002, HSDS worked as a Consultant at Citibank NA, Colombo and Packserve (Pvt) Ltd. Then he continued his career in leasing as the CEO of Commercial Leasing Company Ltd from 2002 to 2010. After his retirement from CLC, in addition to Directorships at Maskeliya Plantations PLC (a member of the Richard Peiris Group of Companies) and Siyapatha Finance PLC (a fully owned subsidiary of Sampath Bank PLC) both Public Quoted Companies he is also a Director of many private companies, HSDS has started spending a significant amount of his time in real estate and apartment development, formalizing his commitment by joining STK. He is also extensively involved in the operation and management of agricultural properties and is an active pioneer investor in the Sri Lankan share market.