In a slow-motion race of two retail behemoths, Amazon's trump card was its lucrative cloud-computing business.

The shuffle underscores the rivalry between the two retailers, particularly as Walmart expands its advertising and third-party marketplace businesses.

Amazon has surpassed Walmart as the world’s largest company, measured by sales, breaking Walmart’s 13-year streak at the top of the list.

Amazon prides itself on being data obsessed, and its approach to tracking its own employees’ use of AI has been no different.Amazon has been using an internal system called Clarity to track how often ...