Yahoo made waves when it hired Marissa Mayer as its new CEO earlier this year, and not just because the move made her one of the most visible female chief executives in an industry with a poor history of elevating women into leadership roles. The choice was admired by analysts and tech observers, who praised Mayer for her reputation as a brilliant engineer and for her work as a top executive at Google. Mayer has gotten high marks for her role in unloading much of Yahoo’s stake in Chinese Internet firm Alibaba, but the bulk of her work is still ahead as she tries to leverage her firm’s vast audience and technological assets into a formula for revenue growth.