Amazon CEO Andy Jassy announced in November that the company would begin laying off employees across multiple departments, and suggested terminations are likely to continue into 2023. Jassy’s comment came days after the New York Times reported the company had plans to lay off around 10,000 employees across its devices, retail, and human resources divisions.

Jassy justified the mass layoffs on Wednesday at the New York Times DealBook Summit, citing economic uncertainty ahead that prompted the company to cut back on expenses. “We just felt like we needed to streamline our costs,” he said.

But at the same time, Jassy defended the wave of hiring and explosive growth Amazon has enjoyed over the past few years, despite the abrupt about-turn the company has been forced to take this year.

Amazon’s retail business grew tremendously during the early days of the pandemic, and at one point the company was adding as many as 1,400 new hires a day. “It forced us to make decisions at that time to spend a lot more money and to go much faster in building infrastructure than we ever imagined we would,” Jassy said Wednesday.

“We knew we might be overbuilding,” he added.

Amazon’s cost-cutting measures this year were sparked by a darkening economic environment for tech sector companies, many of which have also resorted to layoffs to keep expenses down. Twitter, Meta, and Microsoft have announced cuts this year too, and many have called out a similar culprit: falling demand for tech products as the lockdown stage of the pandemic faded.

Amazon did not immediately reply to Fortune’s request for comment.

One of the Amazon divisions going through layoffs is its devices department, which has been a drain on the company in recent years. The unit, which in the past had over 10,000 employees working on devices including Alexa and Echo, may have been losing the company as much as $5 billion annually in recent years, the Wall Street Journal reported last month.

Weak sales in devices have seen Amazon lean on other units including its advertising operation—which generated $31.2 billion in revenue last year—as well as sales. But despite entering its traditionally busy holiday season, Amazon warned during its last shareholder meeting in October to expect lower sales in the future after reporting dismal earnings that fell short of Wall Street expectations.

The company’s managers said they expect fourth quarter revenue this year to be between $140 billion and $148 billion, which would represent annual growth of just 2% to 8%, far below the 10% annual growth the company managed during the fourth quarter of last year.

Amazon’s bad earnings report prompted Bank of America analysts to claim that “the recession may be here already” as consumer spending shows signs of slowing down.

But that outlook may have been boosted by the record-strong start to the holiday season retailers observed this week. Consumers spent a record $11.3 billion on Cyber Monday, according to Adobe Analytics, and the company announced on Wednesday that the Thanksgiving holiday shopping weekend had been “record-breaking” and its “biggest ever.”