David Zaiken has over 45 years international tax experience advising clients on a global basis and is currently a senior leader of Grant Thornton’s West Coast International Tax Practice. Prior to joining Grant Thornton joining the firm’s West Coast practice, David was a core member of the firm’s National Tax Office based in Washington D.C. David also served as the Associate Vice President of International Tax Planning at Weatherford (a large oil field services company). David has been part of numerous international tax planning and controversies throughout his career that involved both corporate and transfer pricing matters. David has helped clients manage the changing geography of global tax planning under tax reform in both the U.S. and under Pillar one and two and other Base Erosion and Profit Shifting (BEPS) changes. David is a core international tax committee member of the United States Council of International Business and participates in commenting on various OECD and other matters. David has particular expertise in taxation and planning for global supply and value chain matters.