Andrew Matthews/PA Images via Getty Images The test models of Amazon's Alexa-powered devices frustrated employees and even Jeff Bezos. Engineers once heard Bezos tell the device to "shoot yourself in the head," a new book says. Other testers said it was a stupid product and would hardly respond correctly. When Amazon was testing what would eventually become Alexa, some workers and even the company's CEO, Jeff Bezos, were frustrated with its performance, according to a new book about the business. Bezos tested an Alexa-powered device — a project referred to as the "Doppler" — at his home in Seattle. "In pique of frustration over its lack of comprehension, he told Alexa to go 'shoot yourself in the head,'" Brad Stone wrote in his book "Amazon Unbound: Jeff Bezos and the Invention of a Global Empire," released on Tuesday.