• Home
  • Latest
  • Fortune 500
  • Finance
  • Tech
  • Leadership
  • Lifestyle
  • Rankings
  • Multimedia

Trendingnow

1

Trump, who has repeatedly called climate change fake, is now threatening Brazil with tariffs over the deforestation of the Amazon

2

Pentagon accuses Alibaba, Baidu and BYD, three of China's biggest companies, of supporting the Chinese military

3

Current price of oil as of June 8, 2026

1

Trump, who has repeatedly called climate change fake, is now threatening Brazil with tariffs over the deforestation of the Amazon

2

Pentagon accuses Alibaba, Baidu and BYD, three of China's biggest companies, of supporting the Chinese military

3

Current price of oil as of June 8, 2026
Tech@Work

At Zulily, a small approach to big data

By
Jennifer Alsever
Jennifer Alsever
Down Arrow Button Icon
By
Jennifer Alsever
Jennifer Alsever
Down Arrow Button Icon
October 19, 2014, 3:00 PM ET
Paul Bradbury—Getty Images/OJO Images RF

Racks of clothes, piles of toys, and stacks of boxes clutter the offices and rooms inside the Seattle headquarters of online retailer Zulily. Each day, 9,000 new products are added to the company’s website to be sold in flash sales. Each day, Zulily staff takes thousands of photographs of those products—everything from canvas shoes and leather boots to jewelry and plastic doll houses. Upstairs, engineering director Mike Errecart has a big job: predict which pictures will most likely make each of Zulily’s 4.1 million customers click the ‘buy’ button, then write software to serve up personalized pages.

The approach to such a big data project? The same as it has always been at the five-year-old startup: Think small. Really small. Only a couple of engineers will tackle this project on their own and they’ll manage to do it in just a few months. They’ll take enormous amounts of data about customers and break it down into small bites, perform small experiments using small customer samples, and check in with senior executives for incredibly short meetings each week.

That culture of small and fast offers a lesson to other companies trying to manage giant pools of data. Amy Webb, founder of the consulting and strategy firm Webbmedia Group, says she consistently hears complaints from big companies that everyone is siloed and they don’t talk to each other. “You cannot work that way in the big data space,” Webb says.

Just as Zappos and Amazon (AMZN) aggressively applied predictive modeling to ensure customer purchases were not a one-time deal, Zulily is following the same growth pattern, if not more accelerated. Sales of the five-year-old startup hit $695 million last year; that number is expected to hit $1.2 billion this year. Its stock price (ZU) soared to $72.75 a share last spring, although it has since hovered around $37 a share.

Zulily’s business is in retail, but its DNA is in technology, using data and machine learning to make decisions. In any moment, the company serves up millions of variations of its home pages, marketing emails, or mobile apps with personalized products. Each screen is tailored to an individual customer based on data like what items and brands each customer likes, where they live, what time of day they shop and what they tend to click on or buy.

In 2013, Zulily set out to take that customer data one step further, building software that could predict which photos resonated with which customer and how. Did the photo of workout pants shown on the model work best for the mother of three in Texas? Or would she click on an image of clothes on a hanger—or maybe an action shot? Does the photo make her more apt to hit buy in the morning or evening? Zulily wanted software that could automatically predict that behavior of millions of customers who visit the site.

The photo project is one of 60 to 80 different big data projects going on at once at the company, and despite more than 1,700 employees, teams rarely surpass four to six people. Standup meetings may last less than 10 minutes, operating on what’s known as “Zulily time.”

“If we get more than 10 people in the room, we’re asking ourselves why,” says Luke Friang, the company’s chief information officer. “It really slows us down with too many ideas and too much input.”

Friang and CEO Darrell Cavens take a relatively hands off approach to those kinds of projects, turning over control to small teams with periodic checkins.

Each morning, Errecart arrives to plan new tests for the photo project. He holds 10-minute standup meetings with two team managers and three software engineers. Then they’re off to write code, sharing work online using online collaboration software. To avoid getting caught up in the minutia of data, Errecart’s team of data scientists will pop in to sit in on a customer focus group or visit with merchandisers and marketers to better understand what customers think. “The engineers we hire spend as much time with customers as they do writing software,” Friang says.

To dissect how photos impact buying decisions, Errecart’s team looked at 15 different shots of a product and tested them on the homepage, watching the activity of a few thousand customers. Did one photo lead to more people putting it in their cart?

They looked at the wealth of data about a product, including color, fit, style, size, brand, and texture. One test told them women who shop in the morning tend to be more tactile when buying and they snap up things more quickly.

Each day and hour, the team tweaks the predictive software based on that kind of information, giving frequent ad hoc updates to the leadership team at Zulily. These miniature experiments let engineers make mistakes, learn from them, and move on. The process is a necessity, due to the massive amount of data generated by the site, Friang says. “It can be completely overwhelming,” he says. “It’s about breaking it down, testing, and trial and error.”

That process may be more challenging as time goes on. Zulily faces stiff competition from the likes of Amazon, Target (TGT), and Walmart (WMT) and flash-sale sites like Fab and Gilt Group. Culling big data is a big advantage. As Zulily grows, so does its data. The company’s greatest challenge ahead? Staying small, of course.

About the Author
By Jennifer Alsever
See full bioRight Arrow Button Icon

Latest in

Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025

Most Popular

Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Fortune Secondary Logo
Rankings
  • 100 Best Companies
  • Fortune 500
  • Global 500
  • Fortune 500 Europe
  • Most Powerful Women
  • World's Most Admired Companies
  • See All Rankings
  • Lists Calendar
Sections
  • Finance
  • Fortune Crypto
  • Features
  • Leadership
  • Health
  • Commentary
  • Success
  • Retail
  • Mpw
  • Tech
  • Lifestyle
  • CEO Initiative
  • Asia
  • Politics
  • Conferences
  • Europe
  • Newsletters
  • Personal Finance
  • Environment
  • Magazine
  • Education
Customer Support
  • Frequently Asked Questions
  • Customer Service Portal
  • Privacy Policy
  • Terms Of Use
  • Single Issues For Purchase
  • International Print
Commercial Services
  • Advertising
  • Fortune Brand Studio
  • Fortune Analytics
  • Fortune Conferences
  • Business Development
  • Group Subscriptions
About Us
  • About Us
  • Press Center
  • Work At Fortune
  • Terms And Conditions
  • Site Map
  • About Us
  • Press Center
  • Work At Fortune
  • Terms And Conditions
  • Site Map
  • Facebook icon
  • Twitter icon
  • LinkedIn icon
  • Instagram icon
  • Pinterest icon

Latest in

Sam Bankman-Fried formally files for pardon—but White House reiterates that FTX cofounder’s odds are slim
CryptoSam Bankman-Fried
Sam Bankman-Fried formally files for pardon—but White House reiterates that FTX cofounder’s odds are slim
By Camila Grigera NaonJune 9, 2026
2 hours ago
A trader works on the floor of the New York Stock Exchange (NYSE) in New York, US, on Wednesday, June 3, 2026
InvestingWall Street
Wall Street dumped nearly $1 trillion in tech stocks by midday—then clawed it back and bought peanut butter and paint
By Eva RoytburgJune 9, 2026
3 hours ago
The entrance to a U.S. Immigration and Customs (ICE) detention facility
North AmericaDepartment of Homeland Security
Texas ICE facility spent $11.5 million on guards, medical services, transportation and meals weeks before the camp even held detainees, GAO finds
By Michael Biesecker, Ryan J. Foley and The Associated PressJune 9, 2026
3 hours ago
AI isn’t replacing Hyatt’s salespeople—it’s freeing up a full day of work every week, according to the CEO
AIBrainstorm Tech
AI isn’t replacing Hyatt’s salespeople—it’s freeing up a full day of work every week, according to the CEO
By Sharon GoldmanJune 9, 2026
3 hours ago
America’s grid is reeling. General Motors offers itself as a distributed utility in disguise
EnergyAutos
America’s grid is reeling. General Motors offers itself as a distributed utility in disguise
By Nick LichtenbergJune 9, 2026
3 hours ago
Tesla cofounder: ‘We should be really worried’ about the U.S. grid as China speeds ahead in the power race
EnergyBrainstorm Tech
Tesla cofounder: ‘We should be really worried’ about the U.S. grid as China speeds ahead in the power race
By Jordan BlumJune 9, 2026
4 hours ago

Most Popular

Trump, who has repeatedly called climate change fake, is now threatening Brazil with tariffs over the deforestation of the Amazon
Environment
Trump, who has repeatedly called climate change fake, is now threatening Brazil with tariffs over the deforestation of the Amazon
By Sasha RogelbergJune 8, 2026
1 day ago
Pentagon accuses Alibaba, Baidu and BYD, three of China's biggest companies, of supporting the Chinese military
Asia
Pentagon accuses Alibaba, Baidu and BYD, three of China's biggest companies, of supporting the Chinese military
By Kate O'Keeffe and BloombergJune 8, 2026
1 day ago
Current price of oil as of June 8, 2026
Personal Finance
Current price of oil as of June 8, 2026
By Joseph HostetlerJune 8, 2026
1 day ago
'We are rapidly running out of time': Watchdog sounds Social Security alarm after 22% cut confirmed for 2032
Economy
'We are rapidly running out of time': Watchdog sounds Social Security alarm after 22% cut confirmed for 2032
By Nick LichtenbergJune 9, 2026
8 hours ago
Gen Zers are arriving at college unable to even read a sentence—professors warn it could lead to a generation of anxious and lonely graduates
Success
Gen Zers are arriving at college unable to even read a sentence—professors warn it could lead to a generation of anxious and lonely graduates
By Preston ForeJune 7, 2026
2 days ago
Costco CEO Ron Vachris rose from forklift driver to the C-suite without a college degree: ‘Don’t chase a title’ is the career advice that got him there
Success
Costco CEO Ron Vachris rose from forklift driver to the C-suite without a college degree: ‘Don’t chase a title’ is the career advice that got him there
By Preston ForeJune 8, 2026
1 day ago

© 2026 Fortune Media IP Limited. All Rights Reserved. Use of this site constitutes acceptance of our Terms of Use and Privacy Policy | CA Notice at Collection and Privacy Notice | Do Not Sell/Share My Personal Information
FORTUNE is a trademark of Fortune Media IP Limited, registered in the U.S. and other countries. FORTUNE may receive compensation for some links to products and services on this website. Offers may be subject to change without notice.