Fleiss will lead Code Eight, a startup that will develop personalized shopping experiences.
Fleiss is the co-founder and former head of business development of Rent the Runway, a fashion rental company.
Store No 8, started in March to develop Wal-Mart's e-commerce business, plans to work with startups that concentrate in areas such as robotics, virtual and augmented reality, machine learning and artificial intelligence.
(What will move markets this quarter and how should investors position themselves ahead of time? Jim Cramer sat down with four of TheStreet's top columnists recently to get their views. Click here to listen to his latest Trading Strategies roundtable with them and read their advice for stocks, bonds, forex and gold.)