Don’t call Amazon Go a convenience store.

Executives with Seattle-based insist the cashierless retail concept is not about the box or even the tech but instead about delivering a modern customer experience.

“We asked ourselves: Wouldn’t it be cool if you could just walk in, take stuff and leave? No friction, kind of like it was your own pantry or refrigerator at home,” Gianna Puerini, vice president of Amazon Go, tells CSP in an exclusive interview.

Making this experience a reality—and a seemingly effortless one—was the challenging part. “It’s incredibly hard to pull this off using technology that completely recedes in the background so that when the customer shops, they’re immersed in a seamless shopping experience,” says Dilip Kumar, Amazon Go’s vice president of technology.

Puerini, Kumar and the Amazon team worked for several years to build the technology that powers Amazon Go, ultimately combining computer vision, sensor fusion and deep learning—the kind of tech behind today’s self-driving cars. The result was Amazon Go as it is known today: an automated shopping experience that replaces waiting in line with walking away.

About one year after the first Amazon Go store opened in Seattle, the system continues to learn and improve. “From a technology perspective, although the overall ‘just walk out’ shopping experience is the same in all our stores, our custom-built machine-learning algorithms continue to get smarter, by design, over time, and also require less data to recognize products and generate accurate receipts,” Kumar says. There are seven Amazon Go stores open to the public so far, spread among Seattle, Chicago and San Francisco.

“Density and office workers align to what the store does well: serve a lot of people in a rush, usually pressed for time and hungry,” Puerini says. These types of customers are central in choosing markets for new locations.

“It’s not technology for technology’s sake. It’s technology being used to enhance a customer experience,” says George Blankenship, a former executive with Apple and Tesla. “That’s what Amazon does. They start with the customer and then figure out: What would the customer want, and how could we give it to them better than anybody else?”

The Amazon Go team continues to learn about these customers’ shopping habits. For example, it was surprising how many snack and beverage purchases take place during the midafternoon, with some customers returning multiple times during the day, “just because it is so easy,” Puerini says. Two of the top sellers across all Amazon Go stores: the Chicken Banh Mi sandwich and Amazon Meal Kits, which provide the ingredients to make a meal for two in about 30 minutes.

As with any evolution in technology, Amazon Go has been met with a flurry of rumor and speculation. Could “just walk out” tech launch in Amazon’s full-size Whole Foods Market grocery stores? Will Amazon, as Bloomberg reported, open 3,000 Amazon Go stores by 2021? The team behind Amazon Go isn’t showing its cards. “We are focused on our stores in Seattle, Chicago and San Francisco now,” Puerini says, “and I don’t have my crystal ball with me today, so we will all have to wait and see.”