Serial entrepreneur and Jet.com Founder Marc Lore is retiring as Walmart’s CEO of eCommerce to help startups and write a book while pursuing his passion of developing a city of the future.

In an interview with Recode on Friday (Jan. 15), Lore said his dream pursuit is to create “a city of the future” built on a framework that envisions “a reformed version of capitalism.”

Lore joined Walmart after selling his startup Jet.com to the retail giant for $3 billion in 2016. He officially leaves his post on Jan. 31 but will continue to serve as an advisor to Walmart through September to fulfill his 5-year contract, according to the K1 filing with the SEC.

Before Jet.com, Lore founded several eCommerce and internet companies, including Quidsi, the former parent of Diapers.com, now owned by Amazon; and The Pit, an eBay alternative now owned by Topps. Walmart merged the Jet.com team with its Walmart.com team and last year unified its physical stores with its eCommerce unit, according to the filing.

“Our Walmart U.S. segment has been operating and continues to operate as an omnichannel business,” per filing.

Lore was responsible for engineering the transformation of Walmart’s online business, including overseeing the redesign of the company’s website and app, Walmart CEO Doug McMillon told CNBC in an email. Lore also overhauled the retailer’s supply chain for two-day and same-day delivery. McMillon praised Lore’s ability to quickly accelerate eCommerce growth and meet the digital demands brought about by COVID-19.

“Marc’s leadership helped ensure we were positioned to respond to the demand driven by the pandemic this year,” said McMillon, per CNBC. “All of this progress is the result of good work from a lot of people, of course, but Marc’s expertise and aggressiveness have been game-changing. We have learned a lot from him. I have personally learned a lot from him.”

Walmart’s foray into delivery memberships with Walmart+ could help the retailer capture more of the consumer’s whole paycheck, according to an exclusive research project from PYMNTS. Some 17 percent of U.S. consumers surveyed had a Walmart+ membership, about a month after it launched in September 2020. Some 68 percent of respondents said they had an Amazon Prime member. Amazon launched Prime in February 2005 and grew it to more than 150 million members globally.