At Apple, he was renowned as one of the "godfathers" of the iPod — music's hottest device since the Walkman.
So when Tony Fadell left the company in 2008 and co-founded a start-up with another Apple engineer, there was considerable interest in what the pair was working on.
After an 18-month wait, tech insiders were a little underwhelmed when Fadell announced his next project was not a cutting-edge entertainment device but a thermostat.
However, having sold his three-year-old company Nest to Google for $US3.2 billion ($3.5 billion) on Monday, those same detractors might now think otherwise.
The deal is the second-largest in Google's history, after its $US12.5 billion acquisition of mobile phone maker Motorola in 2011, comfortably eclipsing the $US1.6 billion they paid for YouTube in 2006.
Fadell may have kept his word when he told the late Steve Jobs he would never compete with Apple products after leaving the company, but his start-up has certainly poached a lot of Apple talent. According to LinkedIn, there are 97 former Apple staff among Nest's team of 280. A number of former Google employees also work there.
Nest is best known for its smart thermostat, which learns your habits over time and adjusts heat settings accordingly. It was created in a garage in Palo Alto, California.
According to a report by GigaOM in January last year, the start-up was shipping 40,000 to 50,000 of its Nest thermostats a month and was valued at $US800 million after a $US80 million funding round.
As well as selling thermostats, the start-up recently branched out into selling a smart smoke and carbon monoxide detector, the Nest Protect. Unlike a traditional smoke detector, it speaks with a human voice and gives you the option to turn it off with a wave of your hand if there is no emergency.
The Nest purchase ratchets up competition with Apple in the connected-device market, where web-based software meets hardware. It also deepens Google's role in the so-called "Internet of Things" market – an industry of wireless, connected gadgets that could create between $US2.7 trillion and $US6.2 trillion of economic value annually by 2025, according to the McKinsey Global Institute.
As part of the acquisition, which has again raised fears of a bubble in technology company valuations, Google will gain access to Nest's staff, including its founders.
"I'm not trying to ride off into the sunset," Fadell told Bloomberg, regarding the sale. "I want to build a vision, build it out."
Spending billions on Nest Labs "indicates to me that Nest has a lot more up their sleeves than any of us might imagine at this moment", Rick Thompson, president of renewable energy market research firm Greentech Media, told the Los Angeles Times.
"Google is putting a stake in the ground that these smart homes and connected homes are going to be very real".
In addition to its internet search engine, Google is designing wearable computing devices, such as Google Glass smart eyewear. The company has also invested in software for computers, mobile devices, driverless cars, robots and televisions.
"It's a further push into consumer hardware as a way to control knowledge of the user," Carolina Milanesi, a director at market research firm Kantar Worldpanel, told Bloomberg.
"Google is going to use the information to see what other products they can come up with."
"This is a very interesting move that creates a lot of questions about where Google will try to go next in the home," Gartner analyst Chet Geschickter told the Los Angeles Times. "Will they get into home security? Will they try to do over the top entertainment services with cable TV and set-top boxes? Will they get into communications inside the home? Will they branch out into more parts of home energy management and home automatisation?"
Fadell's vision vision to build a music player in the '90s began when he started his own company called Fuse to develop the device, but failed to secure a second round of funding to get it off the ground.
After a short stint at internet music streaming company RealNetworks, he joined tech giant Apple in 2001 and went on to become known as one of the "godfathers" of the iPod for his work on the first generations of the music player.
While at Apple, Fadell, 44, developed a reputation for his forceful personality and occasionally clashed with other executives, including former mobile software head Scott Forstall during the iPhone's development, Bloomberg Businessweek reported in 2011.
After retiring from Apple at the end of 2008, he later returned to co-found a start-up working on the next generation of the thermostat in 2010, which was eventually unveiled in late 2011.
Another engineer who left Apple to start Nest with Fadell, Matt Rogers, said in a recent interview the decision to leave Apple was difficult.
"It was honestly probably the hardest decision of my life," Rogers said.
"Apple was my dream job. I was making tonnes of money. The stock was on the craziest ride of all time ... my family told me not to do it. My friends told me not to do it, said 'you're crazy.'"
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