Maggie Wu

It has been a year of highs and lows for Alibaba—and particularly Wu, the firm’s CFO of two years: since helping to lead the company’s much ballyhooed IPO in September 2014, the e-commerce giant’s share price has slid 31%. China’s unsettled markets have rattled investors, and slow consumer spending led Alibaba to lower its quarterly estimates in early September. Yet with a market cap of $165 billion, the company remains a juggernaut, and Wu, a 15-year veteran of KPMG who spent some of those years in Silicon Valley, is mission critical. —Erika Fry