Datuk Phang's career in Malaysia's civil service spans over 36 years in promoting foreign and domestic investments. He assisted in developing the manufacturing and services sectors in Malaysia under the Malaysian Investment Development Authority (MIDA), where his last held position was the Deputy Chief Executive Officer before his retirement in 2017.

He began his career in 1981 as an Economist in MIDA where he served in various capacities including Assistant Trade Commissioner for MIDA London and Director of MIDA New York. Upon returning to the MIDA headquarters, Datuk Phang was appointed as the Director of Foreign Direct Investment (FDI), overseeing the promotion of global FDI into Malaysia. He was also involved in organising and participating in many Trade and Investment Missions overseas led by the Prime Minister and Ministers of International Trade and Industry.

Datuk Phang is the Independent Non-Executive Chairman of JF Technology Berhad and UMS Integration Limited, Independent Non-Executive Director of Inari Amertron Berhad and Apex Healthcare Berhad. He has also been appointed as Director of Novugen Pharma Sdn Bhd, Novugen Oncology Sdn Bhd and Kisiwre Sdn Bhd.

He holds a Bachelor of Economics (Honours) from the University of Malaya and has attended several notable Senior Management programmes, namely the Harvard Business School and Institut Européen d'Administration des Affaires ("INSEAD").