This sounds like a company in big trouble and trying desperately to stem attrition and improve tanking morale. According to crunchbase they're basically owned by a private equity firm now (which is rarely a fun place to be) and are raising something like a billion dollars a year -- which basically appears to be around what their operating costs are (employee count of that year * $250k/yr). They're either not bringing…
They are not "basically owned" by a private equity firm. They have raised money at high valuations, and I strongly doubt that they have sold away a controlling stake in the company. So, they still get to make their own decisions. They are definitely bringing in real revenue. Many firms have raised substantially more than they need to, because they have been well aware that funding could dry up.
They've raised 15 rounds that are publicly known. Every single raise since Sep 2013 has been under private equity. This sounds more like the company is being sold on the private market and each new owner is putting in a year's worth of cash infusion for operating costs.
Are those fund raising rounds? I dunno. But it's one of the weirdest fund raising profiles I've ever seen.