Upwork went public last fall (Oct 2018) and is a publicly traded stock. As such, their financials are also public. Upwork has yet to make a profit. It is my hope that Upwork will become profitable as that will be a benefit to all of us - if they manage to stay in business.
So long as all obligations are met (overhead, salary, various expenses, etc.) are met, a company can remain in business indefinitely without turning a profit, as that's just what's left over after you subtract expenses from revenue.
Going public can definitely harm a company, however, because then making a profit is required. And, as is sadly the case anymore, investors increasingly demand that profits go up every quarter, rather than look at long-term viability. They want short-term gain at the expense of possibly higher future earnings. This can lead a business to cut corners in order to satisfy those demands, and that's where things get really dicey and cause a lot of companies to fail after their IPO.