I think the operational details naturally were arrived at by hill climbing (or descent), as you suggest. However, I suggest that you read pg's early essays, mos

I think the operational details naturally were arrived at by hill climbing (or descent), as you suggest. However, I suggest that you read pg's early essays, most of the basic vision that went into YC, the no-nonsense "make something that people want" approach is there. That's why YC was successful, if they didn't start from such an initial condition they would have been just another incubator and there are hundreds of them.