The company has almost 900 jobs open, representing nearly 8 percent of its workforce.
The internet giant bought the money-losing cellphone maker for $12.5 bn.
It passes user info to the app developer.
The move puts it in competition with Apple, Amazon and Google.
Investors want to see evidence that CEO Mark Zuckerberg's 8-year-old company is delivering on promises to develop a full-fledged mobile advertising business.
She warned investors on Monday that fixing Yahoo was a long-term project.
It would be available on both the desktop as well as on mobile phones apps and tablets.