Tech giants Amazon and Salesforce rang in the new year with massive job cuts, the former announcing thousands of new job cuts and the latter cutting 10% of its workforce. Company executives cited ongoing economic uncertainty and bloated payrolls.

“This year’s review has been more difficult given the uncertain economy and that we’ve hired rapidly over the last several years,” Amazon CEO Andy Jassy explained in a note shared with employees on Wednesday. Jassy said the cuts would impact more than 18,000 employees, and builds on the 10,000 job cuts announced in November.

Those initial cuts were linked to Amazon's Devices and Books business and voluntary reduction offers for employees in its People, Experience, and Technology (PXT) business. Jassy wrote that the latest cuts would impact "several teams ... however, the majority of role eliminations are in our Amazon Stores and PXT organizations." There was no specific mention of any job cuts at its Amazon Web Services (AWS) cloud business.

Amazon counts around 1.5 million full- and part-time employees worldwide.

Jassy explained the changes should help the company pursue long-term opportunities with a stronger cost structure and more strategic headcount planning.

“Amazon has weathered uncertain and difficult economies in the past, and we will continue to do so,” he wrote. “I’m also optimistic that we’ll be inventive, resourceful, and scrappy in this time when we’re not hiring expansively and eliminating some roles. ... Companies that last a long time go through different phases. They’re not in heavy people expansion mode every year."

Salesforce's cuts will impact more than 7,000 employees at the cloud services giant and also includes real estate and office divestitures.

“The environment remains challenging and our customers are taking a more measured approach to their purchasing decisions," Salesforce co-CEO and co-Founder Marc Benioff wrote in a letter to employees. "With this in mind, we’ve made the very difficult decision to reduce our workforce by about 10%, mostly over the coming weeks."

Benioff took blame, noting Salesforce hired too many new employees in the face of a slowing economy. “As our revenue accelerated through the pandemic, we hired too many people leading into this economic downturn we’re now facing, and I take responsibility for that," he wrote.

The layoffs are expected to be complete by the end of the company’s fiscal year of 2024, and affected employees based in the U.S. will get a minimum of five months of pay, along with other benefits to help with their transition, according to Salesforce. The company noted in a Securities and Exchange Commission (SEC) 8-K filing it would incur between $1.4 billion and $2.1 billion in charges connected to the cuts, with up to $1 billion linked to its fourth fiscal quarter of 2023.

The job cuts come on the heels of recent leadership changes. Salesforce announced in November that its co-CEO and Vice Chair Bret Taylor will step down at the end of this month and that Slack CEO Steward Butterfield will also leave Salesforce this month. Salesforce acquired Slack for around $27.7 billion in 2020.