John Siak worked at General Motors Research and Development Center from 1978 to 1998, and then at the Powertrains Division, Casting Development and Validation Center from 1998 to 2005. John served as an ACA board member from 1980 to 1990 and was involved in fundraising at the Far Eastern Festival and other local municipal festivals. He served on the Chinese Community Center site selection committee, and served as chair of the CCC Renovation Committee in 2005-2006.