• Incoming Amazon CEO Andy Jassy, who has run Amazon's cloud business for the past 15 years, revealed the identity of his replacement to employees in a memo.
• Adam Selipsky left Amazon in 2016 after 11 years to run Tableau, and he sold Tableau to Salesforce in 2019.

Amazon has chosen to Adam Selipsky, currently CEO of Salesforce-owned data-visualization software maker Tableau, to run its Amazon Web Services division. Andy Jassy, the current head of AWS and the person chosen to replace Jeff Bezos as the head of all of Amazon, informed employees in an email on Tuesday.

Amazon rules the market for public cloud infrastructure that companies use to run internal and external applications, a modern alternative to relying on in-house servers, storage and networking equipment. In 2019 industry research company Gartner estimated that Amazon had 45% of the market, more than any other company, including Microsoft and Google. As such, Selipsky becomes the most visible person in the growing category, perhaps second only to Jassy, who enters a bigger job when he becomes Amazon CEO in the third quarter.

Selipsky is one of the people several insiders had identified as a possible successor to Jassy. The two men have an excellent relationship, a person familiar with the matter told CNBC. Selipsky had held a prominent position inside AWS, as vice president for sales, marketing and support, before leaving to run then-public Tableau in 2016. Salesforce bought Tableau for $15.7 billion in 2019.

The role Selipsky left at Amazon was vacant for years. Last year AWS chose executive Matt Garman, who had worked on AWS' core EC2 virtual-computing service, to take over the position.

Selipsky was viewed as a rising star within Salesforce after the Tableau acquisition. At an event hosted by Goldman Sachs in January, the bank's CEO David Solomon asked Salesforce CEO Marc Benioff to name something that investors aren't fully appreciating about his company. As part of his answer, Benioff listed a few top executives.

We "have so many other CEOs in our midst like Adam Selipsky, the CEO of Tableau," Benioff said. "Soon, we'll have Stewart, CEO of Slack," he added, referring to Stewart Butterfield.

Salesforce CFO Mark Hawkins responded to a question about the Tableau integration in December. He said: "It's a best-in-class, unique asset in the world. Great leadership team, great CEO with Adam Selipsky and the management team."

Selipsky has remained president and CEO of Tableau since the acquisition. Mark Nelson, who joined Tableau as an executive vice president of product development in 2018 from SAP-owned expense-management service Concur, where he had been technology chief, will become the new head of Tableau, a Salesforce spokesperson told CNBC in an email. Nelson starts in the new job immediately, according to a person close to Salesforce, while Selipsky will return to Amazon on May 17, Jassy wrote in the memo.

Selipsky joined Amazon in 2005, a year before the company introduced EC2 and the S3 storage service, and stayed for 11 years. Before that he had been a vice president at RealNetworks.

A copy of the memo follows. Amazon later confirmed the move in a blog post.

I want to share that Adam Selipsky will be the next CEO of AWS.

Adam is not a new face to AWS. Back in 2005, Adam was one of the first VPs we hired in AWS, and ran AWS's Sales, Marketing, and Support for 11 years (as well as some other areas like our AWS Platform services for a spell). Adam then became the CEO of Tableau in 2016, and ran Tableau for the last 4.5 years. Tableau experienced significant success during Adam's time as CEO-- the value of the company quadrupled in just a few years, Tableau transitioned through a fundamental business model change from perpetual licenses to subscription licensing, and the company was eventually acquired by Salesforce in 2019 in one of the largest software acquisitions in history. Following the acquisition, Adam remained the CEO of Tableau and was a member of Salesforce's Executive Leadership Team.

Adam brings strong judgment, customer obsession, team building, demand generation, and CEO experience to an already very strong AWS leadership team. And, having been in such a senior role at AWS for 11 years, he knows our culture and business well. 

With a $51B revenue run rate that's growing 28% YoY (these were the Q4 2020 numbers we last publicly shared), it's easy to forget that AWS is still in the very early stages of what's possible. Less than 5% of the global IT spend is in the cloud at this point. That's going to substantially change in the coming years. We have a lot more to invent for customers, and we have a very strong leadership team and group of builders to go make it happen. Am excited for what lies ahead.

Andy

 P.S. Adam will return to AWS on May 17. We will spend the subsequent several weeks transitioning together before making the change sometime in Q3.

-- CNBC's Ari Levy contributed to this report.