Meta, which owns Facebook, Instagram and WhatsApp, has announced that it will cut 10,000 jobs.
It will be the second series of mass redundancies from the tech giant, which laid off 11,000 employees in November 2022.
Meta chief executive Mark Zuckerberg said the cuts would be "tough", and formed part of a "year of efficiency".
In addition to the 10,000 jobs being lost, 5,000 open roles at the company will be left unfilled.
Mr Zuckerberg told staff in a memo he believed the company had suffered "a humbling wake-up call" in 2022 when it saw a slowdown in revenue.
Meta previously announced that, in the three months to December 2022, earnings were down 4% year-on-year - though it still managed to make a profit of more than $23bn over the course of 2022.
Mr Zuckerberg cited higher interest rates in the US, global geopolitical instability and increased regulation as some of the factors affecting Meta.
"I think we should prepare ourselves for the possibility that this new economic reality will continue for many years," he said.
The cuts come as companies including Google and Amazon have been grappling with how to balance cost-cutting measures with the need to remain competitive.
At the start of this year, Amazon announced it planned to close more than 18,000 jobs because of "the uncertain economy" and rapid hiring during pandemic, while Google's parent company Alphabet made 12,000 cuts.
According to layoffs.fyi, which tracks job losses in the tech sector, there have been more than 128,000 job cuts in the tech industry so far in 2023.
Mr Zuckerberg said the recruitment team would be the first to be told whether they were affected by the cuts, and would find out on Wednesday. He also outlined when other teams would know about their futures.
"We expect to announce restructurings and layoffs in our tech groups in late April 2023, and then our business groups in late May 2023," he wrote in a memo to employees on Tuesday.
"In a small number of cases, it may take through to the end of the year to complete these changes.
"Our timelines for international teams will also look different, and local leaders will follow up with more details."
Sadly, we're getting used to hearing about big tech layoffs, as the giants continue to tighten their belts. Many like Meta make most of their money from carrying advertising.
And now they're faced with a perfect storm of falling ad revenues from companies with their own bills to pay, and a user base which has less money to spend, making existing ad space less valuable.
It's interesting to note that Meta is looking to its recruitment team in the latest round of cuts.
I often hear that Silicon Valley firms have a tendency to over-recruit, for two reasons. Firstly, so they have staff ready to handle sudden enormous growth, which can happen (just look at TikTok), and secondly, to hire and retain those they perceive to be "top tech talent", and who they do not want working for their rivals instead. Both are luxuries, it seems, that are no longer affordable.
Meta has the added risk of Mark Zuckerberg's enormous gamble on the metaverse being The Next Big Thing. If he's right, his firm will regain its crown, but if he's wrong, the $15bn+ dollars he has spent on it so far could disappear in a puff of mixed reality smoke.
Mr Zuckerberg said there would be no new hires until the restructuring was complete, and said he aimed to make the company "flatter" by "removing multiple layers of management".
He also dedicated a section of the correspondence to hybrid work, and said software engineers who joined Meta in-person performed better than those who joined remotely - indicating that this would change as part of the company's "year of efficiency".
"Engineers earlier in their career perform better on average when they work in-person with teammates at least three days a week," he added.
"We're focusing on understanding this further and finding ways to make sure people build the necessary connections to work effectively.
"In the meantime, I encourage all of you to find more opportunities to work with your colleagues in person."
After President Emmanuel Macron pushed his unpopular pension bill through Parliament without a vote, demonstrations about the changes broke out again.