In a letter to employees first published by CNBC, chief executive Dara Khosrowshahi said Uber needs to react to a “seismic shift” in markets.

“While investors don’t run the company, they do own the company—and they’ve entrusted us wit h running it well,” he said in the note, which was sent on Sunday.

He added that Uber’s focus had shifted from profitability to free cash flow.

While Khosrowshahi insisted that Uber will “meet the moment,” he told workers that this means making tradeoffs.

“We have to make sure our unit economics work before we go big,” he said. “The least efficient marketing and incentive spend will be pulled back. We will treat hiring as a privilege and be deliberate about when and where we add headcount. We will be even more hard-core about costs across the board.”

Khosrowshahi appealed directly to employees, noting that the company’s average worker is “barely over 30,” which means most of the company’s workforce has spent their career “in a long and unprecedented bull run.”

“This next period will be different, and it will require a different approach,” he said. “In some places we’ll have to pull back to sprint ahead. We will absolutely have to do more with less. This will not be easy, but it will be epic.”

Uber posted a $5.9 billion loss when it published its first-quarter earnings last week, most of which was attributed to a drop in value of the company’s stakes in other firms, including Chinese ride-hailing giant Didi.

However, the company’s revenue for the first quarter grew 136% year-on-year, with Khosrowshahi saying the results show there has “never been a more exciting time to innovate at Uber.”

In 2020, Uber carried out mass layoffs, letting go of more than 3,500 employees—or 14% of its workforce—in early May. Just weeks later, the company laid off a further 3,000 workers and said it would close or combine 45 global offices.