Michael Lebowitz, who just joined Mayer Brown’s tax practice as a partner in Los Angeles, has a sharp read on the Big Four accounting firms’ ambitions for delivering legal services in the United States.

That’s because the international tax adviser just spent the last two years as a managing director in PwC’s tax practice. In fact, Lebowitz has spanned the Big Law/Big Four divide throughout his 35-year career, having also served as a partner at KPMG, in addition to partnerships at White & Case, DLA Piper and Baker & McKenzie.