Top engineer poached from Google to lead Yahoo

Marissa Mayer becomes Yahoo's fifth chief executive in five years

Marissa Mayer, the twentieth employee to join Google 13 years ago, will become Yahoo's fifth CEO in five years after leaving the web giant last night.

Mayer will start at Yahoo immediately.

"I am honoured and delighted to lead Yahoo," said Mayer in a statement. "I look forward to working with the company's dedicated employees to bring innovative products, content and personalised experiences to users and advertisers all around the world."

Yahoo co-founder David Filo said: "Marissa is a well-known, visionary leader in user experience and product design, and one of Silicon Valley's most exciting strategists in technology development. I look forward to working with her to enhance Yahoo's product offerings for our 700 million unique monthly visitors."

Mayer holds a bachelors degree in symbolic systems and a masters degree in computer science, both from Stanford University. She specialised in artificial intelligence in both degrees. She is also behind a number of patents in artificial intelligence and interface design.

Mayer is credited with creating and guarding Google's uncluttered "look and feel". She has also been involved in the development of more than 100 features and products including, most recently, the company's suite of local and geographical products encompassing Google Maps, Google Earth, Zagat, Street View and local search for desktop and mobile.

Mayer's experience in creating and delivering products, and her focus on ‘user experience', is sorely needed at Yahoo, which has a long record of botched ideas and implementations. Most recently, the company was embarrassed by the leak of 450,000 user names and passwords from Yahoo Voice, which had been stored in plain text - a heinous security flaw.

Yahoo boasts some 700 million monthly users worldwide, but has failed to develop the comprehensive portfolio of free web products that made Google such a formidable - and highly profitable - web company. A pioneer of web search, its search engine technology is now provided by Microsoft's Bing division.

While some analysts have questioned the appointment of an engineer, rather than a professional CEO, to run Yahoo, former employee Chris Sacca told the New York Times newspaper that "her ship was the tightest run as well as the most rewarding for the members of her team".