Meta, which owns Facebook, Instagram and WhatsApp, has announced plans to cut 10,000 jobs.
It will be the second wave of mass redundancies from the tech giant, which laid off 11,000 employees last November.
Meta chief executive Mark Zuckerberg said the cuts - part of a "year of efficiency" - would be "tough"
In addition to the 10,000 jobs cut, 5,000 vacancies at the firm will be left unfilled, he told staff.
In a memo, Mr Zuckerberg told employees he believed the company had suffered "a humbling wake-up call" in 2022 when it experienced a dramatic 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, and contributing to the slowdown.
"I think we should prepare ourselves for the possibility that this new economic reality will continue for many years," he said.
The latest job 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 the 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.
Timeline for cuts
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 be informed: "We expect to announce restructurings and lay-offs in our tech groups in late April 2023, and then our business groups in late May 2023," he wrote in the memo to staff 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."
Mr Zuckerberg said there would be no new hires until the restructuring was complete, adding that he aimed to make the company "flatter" by "removing multiple layers of management".
He also dedicated a section of his correspondence to hybrid work. His claims that software engineers who joined Meta in person performed better than those who joined remotely, suggest hybrid working will come under scrutiny during the current "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," wrote Mr Zuckerberg.
"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."