As senior vice president and CIO of Amazon.com, Rick Dalzell is the visionary behind the company's legendary e-commerce platform and personalization engine.

Dalzell has overseen US$2 billion worth of technology investment during his decade-long tenure with the e-commerce and technology company. On his watch, the company's IT infrastructure has scaled to support US$10.7 billion in sales, more than 69 million active customer accounts, 42 product lines from apparel to video games, more than 1.1 million third-party sellers, and a growing contingent of software engineers who are tapping into the computing prowess and Web services the company has developed over the years. Then there are all the technological innovations the company's legion of software engineers have brought to market, many under Dalzell's leadership, to make shopping online a piece of cake for consumers: 1-Click ordering, the A9 search engine, product recommendations, wish lists and order updates, among others.

The IT platform Dalzell has overseen is viewed as Amazon.com's core competency, a competitive differentiator and a monumental achievement. CIO.com visitors voted it a wonder of the IT world. Jeffrey Lindsay, a senior analyst with the research arm of investment bank Sanford C. Bernstein, says it's the world's leading online retail platform and calls out its ability to tailor the e-commerce site to each individual customer who logs in. "It delivers a unique user experience in real time to everyone who uses it. It extends to lots of product categories and seamlessly integrates third-party sellers," says Lindsay. "What they're doing [with IT] is extremely difficult and very complicated."

In an interview with CIO in 2001, Dalzell noted that personalization was a way for Amazon.com to achieve its vision of being a customer-centric company. "Very early on, we recognized that we were really in business to help the customer find anything they wanted to buy," he said. "The key was that we were going to need to build a unique store, one that changed all the time, for each individual customer."

Dalzell, a 50-year-old West Point graduate, is now preparing to end a chapter in his career. After 10 whirlwind years, the CIO has decided it's time to pass the baton to someone else, though the company has not yet publicly named a successor. On Aug. 31, 2007, the company quietly announced to its investor community that Dalzell-who joined the fledgling online bookseller in 1997, the year of its initial public offering, from Wal-Mart Stores, where he spent seven years in its information systems division-would be retiring by the end of the year. Dalzell, who maintains a low profile, declined to be interviewed for this story. His retirement presents an opportunity to examine how Amazon.com has changed over the past 10 years, how it executed on its vision, and how it beat investors' skepticism and changed retailing.

Since day one, Amazon.com has been expanding and innovating, with a view toward bringing more products to customers and making the site easier, more convenient and more fun for them to shop through features such as user-generated reviews, product recommendations and the ability to read book excerpts. The company has evolved from a startup bookstore to an established general merchandise retailer on the Web. It began diversifying its product offerings in 1998 with the introduction of its music store in April and movie store seven months later. The website now boasts 42 product categories including auto parts, mechanical components and pet supplies. Last year, it ventured where previous Internet companies met their demise-into groceries.