"I felt a little angry. I felt we had been making progress," he said. "I felt very competitive, I didn't want to lose this project to another team. I really wanted to do a good job on this."
What followed was two weeks of almost continuous work.
"Pretty much nothing else mattered over the next two weeks," he said.
The demonstration in front of Jobs took place in the same, windowless room the team had been using all along. A tower Mac computer was running the software connected to a small LCD screen with touch interface to provide Apple's founder a taster of what consumers wouldn't see for the next two years.
It was a success.
"This was clearly what he was looking for and that he had been asking for. He thought it was great work," said Christie.
Before long, additional security was added and keycards were required to access the corridor where Christie and his team worked. Similar measures were taking place across Apple as other teams began working on different aspects of the iPhone.
It was to be a long, tough two years.
"It was exhausting and it was exciting. From 2005 through to the announcement in January and sale in June 2007, it was pretty much nonstop. You had to be prepared to discuss what you were working on at anytime of the day, any day of the week, any week of the year," he said.
When the day of the unveiling came, Christie was in the audience at Macworld Expo 2007 in San Francisco. Apple's phone had become the subject of considerable speculation and anticipation in the months leading up to the event.
"It was nerve-wracking, we all wanted it to go perfectly. There was a lot of anticipation, we were hoping we were right and that people would get it," Christie said of the feeling among his team.
And consumers did get it.
As soon as the iPhone was launched, Apple saw massive interest. People camped outside stores to buy it and lines stretched around the block at many AT&T stores.
Christie says he went to work that day, stopping at the supermarket to buy "a few bottles of decent champagne" and then celebrated with workers in the office. In the evening, he went for dinner with his family and then drove around to AT&T stores to look at the long lines of people waiting to buy the phone.
"It was astonishing. We knew for at least one day we were a huge success and it had hopefully all been worth it," he said.
Christie came to Apple in 1996 after software he had written for the company's Newton Messagepad, a personal digital assistant, came to the attention of Apple executives. He'd posted some of his applications on a Newton discussion board on CompuServe, one of the online bulletin board systems that predated widespread Internet access, and that led to a couple of contracts at Apple and eventually a job offer.
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