Computer Vision is a fairly recent discipline, rooted in academic research, now emerging as a red hot field. A wealth of commercial applications are being pursued by both startups and large corporations. I have the privilege of straddling both the academic and industry fields, as a professor at USC, now on leave at Amazon, and acted as a consultant to a number of companies: OptiCopy, Geometrix, Poseidon, DXO, Bigstage, PrimeSense. I will review some of the technology developed along the way, and the lessons learned, often the hard way.