It's a great read, though I'm not sure how to take his words in the engineering domain (e.g. what does "3/4 complete" exactly mean?). I don't doubt he is a vary smart guy and also had amazing people; but many years of software <i>engineering</i> have made me quite conservative in terms of estimate.<p>If all the planned components are written, and you can feed the real data into the system and get the reasonable final result out of it, then I'd call it, say, 50% complete; there'd be tedious works after that to make things robust, or find users have unusual settings and you have to adapt to it, etc. Borrowing his rocket metaphor, the rocket without the nosecone is less than half way in terms of development...<p>Of course it really depends on the nature of the product; maybe things like AI engines you can convince the client to pay in the state of "it basically works" and then gradually adapt it to the client's needs afterwards. Also his writing is sometimes sarcastic (which makes the writing enjoyable), so I'm not sure he uses "3/4" or "almost finsihed" in ironic way (that he knows it wasn't "almost finished", but he thought so back then).<p>Anyway, it's so easy to criticize retrospectively. I still respect them for having tackled to such a big problem.