Jeff Bezos will step down as Amazon CEO in the third quarter.

In a letter to Amazon employees published Tuesday afternoon, Bezos announced that he would transition to executive chairman, where he'll focus on "new products and early initiatives."

"Being the CEO of Amazon is a deep responsibility, and it's consuming," Bezos wrote. "When you have a responsibility like that, it's hard to put attention on anything else."

Bezos said that while he will still be involved in important initiatives at Amazon, he plans to spend more time on philanthropy — including the Bezos Earth Fund and his Day 1 Fund — as well as his two other major endeavors: the Washington Post, which he purchased 2013, and his rocket company, Blue Origin.

Andy Jassy, who currently serves as CEO of Amazon Web Services, will replace him. Bezos wrote that Jassy will be an outstanding leader, and that he has Bezos' "full confidence."

Jassy joined Amazon in 1997, the year it went public, and quickly moved up the ranks and is a close confidant of Bezos. He's helped build Amazon's cloud computing business since 2003 into a massive business that generates over $40 billion in annual revenue, and the de facto leader in cloud computing, with over 30% of market share. Insiders say Bezos has unbounded trust in Jassy, who was promoted from AWS's senior vice president to CEO in 2016.

The people who have worked with Jassy, who just turned 53 earlier in January, describe him as a genuinely nice person who nevertheless sets high expectations for his people and expects them to rise to the challenge. Jassy takes Amazon Web Services' role in powering so much of the internet economy — and his role in keeping it on top in the cloud market — very seriously.