OK, yes if you interview 2 people for one job and like both people - you may want to keep the one you didn't hire warm in hopes of a different position becoming available. I wouldn't call that pipelining but its just a name so doesn't matter. However you usually try not to jerk that person around if you do in fact want them working for you some day in the future.Pipelining is arguably an informal process with a lot of nuances. It is somewhat common for folks to be sent offers for roles that are different than what they originally applied for. There could also be some internal horse trading going on -- we need someone for PT now, but I have a better candidate for FT today....but if someone on my FT team bails, I want the PT person to join my team.