Amazon is also grappling with growing labor unrest as its workforce has grown to 1.3 million employees. Over the past year, some of the company’s warehouse workers expressed discomfort about security conditions during the pandemic, forcing Amazon to take immediate action and stop it even more aggressively. More recently, employees at an Amazon fulfillment center in Bessemer, Alabama, have tried to organize a union.

And the competition remains tough. Walmart, the country’s largest retailer and an industry-changing force in itself, recently featured a competitor by the name of Walmart + on Amazon Prime. The company has made huge investments in talent and technology to keep up with Amazon, purchasing Jet.com and a number of other e-commerce companies.

The announcement from Amazon marks the second major change in management last year. In August, Jeff Wilke, the executive director of Amazon’s giant consumer business, said he plans to retire in early 2021 after more than two decades at the company. Dave Clark, who ran the fulfillment and logistics department, has been promoted to replace him.

Mr. Jassy has long been a trusted lieutenant to Mr. Bezos. Mr. Jassy, ​​who grew up in New York, joined Amazon in 1997 when it was still a start-up and took on various roles as the company expanded.

In the early 2000s, Mr Jassy became Mr Bezos’ “shadow” and accompanied him to meetings and business trips. He eventually laid the foundation for Amazon Web Services, the cloud computing business that he developed into a massive engine for innovation and profit. The cloud business generated revenue of $ 45 billion last year, up 30 percent over the previous year.

Mr. Olsavsky said the company will announce Mr. Jassy’s successor as head of the cloud business in the coming months.

“You really had to choose someone for this company, and Andy is the perfect choice,” said Matt McIlwain, managing director of Madrona Venture Group, an early Amazon investor.