In his first letter to Amazon shareholders, CEO Andy Jassy wrote about the enormous growth Amazon experienced during the coronavirus pandemic. The annual shareholder letter, published Thursday, is the first from Jassy since taking over from founder Jeff Bezos last year.

“We realized the equivalent of three years’ forecasted growth in about 15 months,” Jassy said. “We spent Amazon’s first 25 years building a very large fulfillment network, and then had to double it in the last 24 months to meet customer demand.”

As Amazon reported record profits during the pandemic, it also faced logistics and cost challenges while trying to keep up with demand, Jassy said. Amazon quickly scaled up its warehouse network to be able to process more orders. Jassy also vowed to improve injury rates inside facilities.

“We’re also passionate about further improving safety in our fulfillment network, with a focus on reducing strains, sprains, falls, and repetitive stress injuries,” he wrote.

A report released this week by Strategic Organizing Center, a coalition of four labor unions, found Amazon employed 33% of all U.S. warehouse workers in 2021 but was responsible for 49% of all injuries in the industry. Jassy pushed back on the report during an interview with CNBC Thursday morning, saying it was not accurate. In that same interview, Jassy also weighed in on Amazon’s interest in cryptocurrency and NFTs.

“You know, I expect that NFTs will continue to grow very significantly,” Jassy said.

He said he could envision a future where the e-commerce giant sells digital assets whose ownership is recorded on a blockchain.

“I think it’s possible down the road on the platform,” he said.

NFTs have exploded in popularity over the past year, and the technology has some overlap with cryptocurrency enthusiasts. Trading in NFTs hit $17.6 billion last year, an increase of 21,000% from 2020, according to data from Nonfungible.com.