Sit joined the Hong Kong government as an Assistant Electrical and Mechanical Engineer in September 1984 and was promoted to Chief Electrical and Mechanical Engineer in August 2001. He was subsequently promoted to Government Electrical and Mechanical Engineer in December 2007 and to Deputy Director of Electrical and Mechanical Services in September 2011. He rose to Director of Electrical and Mechanical Services in October 2017.
Sit was president of the Hong Kong Institute of Facility Management, the chairman of the Biomedical Division, and the honorary secretary of the Nuclear Division of the Hong Kong Institution of Engineers.
- "Government announces appointment and removal of Principal Officials (with photos)". Hong Kong Government. 20 April 2020.
- "New faces Carrie Lam has enlisted to help Hong Kong tackle coronavirus impact". South China Morning Post. 20 April 2020.
| Secretary for Innovation and Technology
|This article about a person involved in the three branches of government in Hong Kong is a stub. You can help Wikipedia by expanding it.|