David has extensive international management experience in the dairy industry as a Group Managing Director of NZ Milk Ltd; Group Managing Director - Global Operations, General Manager Milk Powder Division for the Dairy Board and Chief Executive of Milk Products Holdings (North America).

David is currently chairman Rangatira Limited and subsidiaries, and Douglas Pharmaceuticals. He is a director of Northport, Excelsa Associates Ltd, and Primeport Timaru.

David is a shareholder in Excelsa Associates Ltd, Taupo Motorsport Park, and Ruapehu Alpine Lifts Ltd. He is a member of the Wellington Branch of the Institute of Directors, College of Queen Margaret College, Royal Wellington Golf Club, Wairakei Tui Golf Club, and The Wellington Club Inc. He also has an interest in New Zealand Rugby.