In the back kitchen of Mountain View's newest pizzeria, Marta works tirelessly, spreading marinara sauce on uncooked pies. She doesn't complain, takes no breaks, and has never needed a sick day. She works for free.

Marta is one of two robots working at Zume Pizza, a secretive food delivery start-up trying to make a more profitable pizza through machines. It's also created special delivery trucks that will finish cooking pizzas during the journey to hungry customers if approved by officials in Santa Clara County, Calif.

Right now Zume is only feeding people in Mountain View, Calif., but it has ambitions to dominate the $9.7 billion pizza delivery industry.

"We are going to be the Amazon of food," said Zume's co-founder and executive chairman, Alex Garden. Garden, 41, is the former president of Zynga Studios. Before that, he was a general manager of Microsoft's Xbox Live. Garden launched Zume in stealth mode last June, when he began quietly recruiting engineers under a pseudonym and building his patented trucks in an unmarked garage.

In October, Zume began working closely with Swiss robot maker, ABB, and a global crew of mechanical, electrical and software engineers. In April, the start-up sold its first cyborg-constructed pie to an unsuspecting customer in Mountain View. People familiar with Zume's fundraising discussions said that Google Ventures as well as Kleiner Perkins Caufield & Byers are considering Series A bids.

Yum Brands Inc.'s Pizza Hut and Domino's have been experimenting with robots, too. Last month, Pizza Hut Asia partnered with MasterCard and Softbank to develop a robotic cashier.

Analysts were quick to raise skepticism about Zume's grand plans, especially considering that Papa Johns, Domino's and Pizza Hut account for 58 percent of the U.S. pizza delivery market. John Glass, an analyst for Morgan Stanley, said that a lack of recognition will make it hard for Zume to compete with bigger names.