SAN JOSE, Calif. – It was 2008, and eBay had a problem. Mark Carges had just arrived to lead the tech side of what the company would come to call the "turnaround" of its core marketplace business. The brand was stale. Revenue was leveling off. And eBay couldn't just blame the recession.

Carges went into the eBay search box and typed "iPod." The first thing that came up was a car.

"I looked at that and thought, this isn't good," Carges says.

Carges, today the company's chief technology officer, says the less-than-relevant result was related to an issue with sponsored links. But that wasn't the point. The company's second-generation search technology was old, and it wasn't working.

"It wasn't just that it needed a new coat of paint," Carges said. "We had lost our innovative approach to building software."

Now eBay believes it's found its way. This month, the company has quietly rolled out to U.S. users its new search engine, known inside the company as Cassini. Users of the site won't notice any obvious cosmetic changes announcing something new under the hood. But eBay hopes they will notice a dramatic narrowing of the gap between wanting and finding. If its engineers were truly successful, eBay will even start showing them the things they want before they know they want them.

Less than a year ago, eBay launched a big redesign that underscored the company's overall effort to rebrand itself. You're not supposed to think of eBay as that site where you can buy and sell used Beanie Babies; it's the place where you can buy and sell anything. And don't call it an auction site (fixed-price sales account for more than 70 percent of eBay purchases, the company says). It's a "global commerce platform." Cassini is eBay's bespoke technology to power that platform's worldwide marketplace. More than just better search results, eBay hopes it's built a new engine for a new identity.

Hugh, Williams, Hugh Williams, eBay, search, search engine Photo: Alex Washburn / Wired Alex Washburn

EBay doesn't get props as a technology company the way archrival Amazon does. Despite his cheery disposition, that lack of cachet clearly bugs Hugh Williams. As eBay's vice president of experience and search, Williams led the Cassini project, a task to which he came well-equipped. Two decades ago, before the spread of the web, Williams had already started to work on search as a way to manage the rapid growth of DNA and protein databases in life sciences research. Later on, just before coming to eBay, Williams was a manager of the team at Microsoft that built Bing. Along with honing his search skills, the Microsoft gig also appears to have left Williams with a lasting love for the Seattle Mariners. The team's memorabilia lines his office—and populates his eBay homepage.

From the product listings eBay is feeding Williams on his homepage, he clearly likes three things: the Mariners, astronauts and shoes. The items roll down Williams' page in what the company calls the Feed, eBay's Pinterest-y way of personalizing visits to the site. Among its many tasks, Cassini is designed to power the Feed with greater precision. Product recommendations based on past searches and purchases might seem like a problem Amazon solved long ago. But Williams says the sheer volume of listings going up and coming down on eBay every day present a unique challenge for search.

Of eBay's 400 million listings, about 20 percent of that inventory leaves the system every day and is replaced by a similar volume of new listings. Prices change. Listings are revised. New signals are emerging constantly.

"This thing has a kind of dynamism I'd never seen before," Williams says.

Engineers at eBay work to funnel that churn to thousands of servers in as close to real time as possible, Williams says. The goal is to index changes within 90 seconds—a demanding enough problem when trying to tame the data parsed by eBay's old search engine, Voyager. To give Cassini the capacity to accomplish the same task while indexing vastly more data, eBay has built a data center from scratch in Utah (the shovel from the groundbreaking is in Williams' office).

From a search engineer's perspective, Williams says to imagine eBay as a collection of buckets, each holding a specific variety of data, such as sellers, buyers, images, text and user behavior. Cassini's job is not just to incorporate more data from more buckets than Voyager, but to learn which new pieces of data inform search result rankings in a way that correlates with success.

Hugh, Williams, Hugh Williams, eBay, search, search engine Photo: Alex Washburn / Wired Alex Washburn

At eBay, success means one thing: something bought, something sold. (Or as the company likes to say, commerce "enabled," a concept that also captures transactions processed by eBay-owned PayPal and its GSI e-commerce infrastructure division.)

Devin Wenig, eBay's president of global marketplaces, says the success of search is measured by "conversion"—that is, a purchase.

"That search for us isn't just about discovery. It's about action," Wenig says.

More than 90 percent of sales start with a search on the site, Wenig says. Even when customers arrive on the site via a Google search, he says eBay's data shows they will still use eBay's own engine to refine their search or to find another product on the site. All that activity amounts to about 250 million searches each day, the company says, (on top of the billions of search queries eBay runs internally every day).

Searching eBay is less like walking up and down supermarket aisles and more like pawing through the racks of the world's largest thrift store.But search means something a little different on eBay than most typical retailers. Unlike most stores, eBay doesn't stock its own "shelves." Instead, eBay depends on more than 25 million sellers to provide its inventory. Since selling on eBay is so radically decentralized, it's also not standardized. You'll never know what you'll find, which makes searching eBay less like walking up and down supermarket aisles and more like pawing through the racks of the world's largest thrift store.

"The ability to look at that incredible long tail of inventory and immediately link it to consumer intent is a very, very hard problem," Wenig says.

Cassini's success will be measured by how much further it goes toward solving that problem than what came before—in other words, by how much better it converts searchers into shoppers. Already, eBay says $175 billion in commerce transpires across its various businesses. To be clear, that's not $175 billion in revenue for eBay. Rather, that's the value of all the goods sold, all the PayPal payments made and business transacted across GSI. By 2015, eBay projects that number will reach $300 billion, a growing portion of which is expected to come from emerging markets around the globe. And Cassini is just one piece of eBay's plan to better bridge the divide between the twin poles of consumerism: "wanting" and "getting."

The unifying aim running through the disparate parts of eBay's business is for the company to insert itself into as many dimensions of consumer retail transactions as possible, regardless of medium, place or step in the process of purchasing. PayPal-powered smartphone restaurant checks. Local couriers ferrying merchandise not just from big local stores to customers, as the company's experimental eBay Now program already does, but from any nearby seller to any nearby buyer. Cash-register apps that let store owners create targeted social media marketing campaigns from right behind the checkout counter.

This is what eBay means by "commerce platform": Finding as many ways as possible for commerce to occur via eBay, which as a company is closing in on doing just about everything but actually selling stuff itself. As eBay undertakes this effort at reinvention, and tries to get the rest of the world to buy in, competitors large and small are seeking to undermine eBay's ubiquity by showing they can handle the individual steps of buying and selling better. Working in its favor, eBay has the advantage of getting there first in so many aspects of online commerce. And now they have a new engine.

"It could really bend the curve of innovation at eBay," Williams says. "It's a platform on which we'll be able to do amazing things." Perhaps—or at least find an iPod on the first try.