Charles is a board member of the International Centre for Trade Transparency and Monitoring. He is also a Visiting Scholar at the Cyber Policy Center at Stanford University, and a member of the Board of Trustees of the Internet Society. He served as an elected member of the Legislative Council in the Hong Kong Special Administrative Region, representing the Information Technology functional constituency, for two terms from 2012 to 2020. After leaving the legislature, he founded Tech for Good Asia, a regional initiative in Asia bringing together businesses and civil societies to harness the positive powers of digital technologies.

As an entrepreneur, Charles co-founded HKNet in 1994, one of the earliest Internet service providers in Hong Kong, which was acquired by NTT Communications in 2000. He was the founding chair of the Internet Society Hong Kong, honorary president and former president of the Hong Kong Information Technology Federation, former chair of the Hong Kong Internet Service Providers Association. He holds a BS in Computer and Electrical Engineering and an MS in Electrical Engineering from Purdue University.