Exactly 10 years ago on Monday, Steve Jobs revealed the iPhone. To grasp the impact of that, one should know that the year was 2007, a time when everyone blithely accepted and believed the "smart" prefix attached to the word "phone" in spite of that term's shortcomings in hindsight — this was true because no one had dared challenged the status quo.

The iPhone: A Revolution

Everyone who had been present in Steve Jobs' keynote address at Macworld bore witness to something that was undeniably a revolution. The iPhone had an unobstructed 3.5-inch display, sans any keyboard peripherals, or cumbersome input methods, such a stylus. "Yuck!" Jobs lamented at the thought during the address. It had multi-touch: no phone had that. It integrated the accelerometer and the proximity sensor to the user interface deftly: no one had done that.

It came with so much more: coverflow, custom pin drops on Maps, streamlined and fluid threaded messaging, visual voicemail, intuitive scrolling, etc. Today, these features aren't noteworthy, but back then, it was all that could be talked, raved, and hyped about. Some would say the iPhone wasn't a revolution, but the same set of folks who do can't deny that it spawned one.

But it could have been a disaster.

iPhone Prototype

"There was tons and tons of different UI development, between both software and hardware development. It was a competing set of ideas, not teams, and we were all working on it," Tony Fadell told The Verge in an interview Wednesday.

The correspondence is great timing. There's been a recent video hurtling across publications, which depicts what's seemingly an iPhone prototype. The device in the video bore no resemblance to the user interface people know well. It instead featured a click wheel: an input method originally found on Apple's iPods.

This was particularly interesting and has naturally became the target of dialogue, since the longstanding story has been that there were two teams that created separate iPhone prototypes — one tried to migrate the click wheel onto the phone, and the other attempted to compact OS X into a tiny device.

The latter concept would later win, of course, if there truly had been such a competition, but there was not, says Fadell, who led the iPod team at Apple before leading the iPhone team.

"The teams were working together. So it wasn't like there were two different people trying different things," he said.

There were indeed two prototypes — only it was actually more focused on UI. One team was trying to design a phone inside an iPod, the other team was designing it with touchscreen in mind.

But the team simply wanted an iPod Video product to work better. To do this, they put a big screen and made the click wheel virtual instead. The input method wasn't going anytime soon because it was "so iconic," said Fadell, but it wasn't working. The click wheel couldn't even be used to dial a number.

"Everything else was working but the one main thing that didn't work was dialing a regular number — it was so cumbersome."

Working With Steve Jobs To Create The iPhone

Fadell says that Jobs was the biggest proponent for the click wheel — he pushed the idea and, in true Jobs fashion, demanded that they make it work, but it didn't work at all. In the end, they had to tell Jobs exactly that.

Fadell recounts helming the division during early development, when the iOS was a nascent concept, and Apple had also considered an embedded Linux project. So there was the OS X UI being developed, and there was a Linux-based OS. Both teams were trying to determine which one was better. Fadell ultimately killed the Linux project, having thought it was the right way to go.

"Steve was happy and all that stuff," he said.

When enough of the touch input was working on the hardware, Fadell knew that they had a winning design. It had been an arduous, taxing process, said Fadell, but the result was excellent.

"It was just, let's burn down all the rest to get this thing to ship."

Fadell and Matt Rogers, a former engineer from Apple, later cofounded Nest Labs, chiefly known for smart thermostats. Google acquired it for $3.2 billion in 2014.

Fadell left Nest in June 2016.