Netflix engages in three kinds of business, or two, really. One is as a rebroadcaster of existing works. It will do deals with whoever the rights holders are for existing movies and series.
In terms of original work, which is, as you say, the $8 billion a year that it's planning to spend worldwide, that's almost the same.... I would say that's exactly the same contracting process as any form of contracting that happens now in the linear universe, which is to say that they either hire a producer who then engages people like me and everyone else—writers, etc.—to provide their services, or they act as a studio and remain a full owner of the show and produce it themselves.
Of course, there's a raging debate internally in all of those organizations as to whether they want to be studios or merely broadcasters, which is an interesting term to use for an SVOD service. They are acting exactly as broadcasters in terms of contracting and getting the work produced.