New CEO Marissa Mayer isn't wasting any time in whipping Yahoo! (NASDAQ:YHOO) into shape.

The inveterate Internet portal has found a new CFO. Not that there was anything wrong with the interim financial chief, Tim Morse, but his replacement would be an upgrade for almost anybody.

Ken Goldman comes in from the CFO position at data security specialist Fortinet (NASDAQ:FTNT), where he helped turn the troubled company into a reliable cash machine over the last five years. It's no coincidence that Fortinet's share price tripled since Goldman joined the company. He's also a noted venture capitalist in his own right. Mayer waved a fond farewell to Morse, then lauded Goldman's track record of financial leadership. The press release also pointed out that Goldman was named one of "America's 15 Most Connected Capitalists" by Forbes. On a personal level, I always found Ken Goldman a rare combination of strong fiscal management skills and deep business knowledge.

The New York Times notes that Yahoo! is replacing a noted cost-cutter with a guy who likes to put money to work. Mayer recently told her staff to expect acquisitions, and Goldman seems like a perfect fit for that strategy. He handled only four minor acquisitions at Fortinet, but then that company never had the deep pockets that Yahoo!'s $1.9 billion of cash equivalents provides.

Yahoo! shares hardly moved on the news, but Fortinet investors will miss Goldman. That stock fell as much as 9% on the announcement.

Mayer faces a huge challenge at Yahoo!, whose former glory has faded in the twin shadows of Google (NASDAQ:GOOGL) and Facebook (NASDAQ:FB). But she brings a decade of very relevant expertise from her time in Google's top echelons, and she's brought her work ethic along for the ride. If anyone can turn the sinking Good Ship Yahoo! around, it's Marissa Mayer. I even have a bullish CAPScall riding on that thesis.

Maybe Facebook should have made a play for Goldman or Mayer. The social network's young management team could use a heavy dose of industry experience, even if they'd only advise founder and leader Mark Zuckerberg. Find out all about Facebook in our premium report, where the Fool's top advisors outline the many challenges and opportunities that lie ahead in the social space. Spoiler alert: I think that Yahoo! poses a credible threat nowadays.