Hard Tack - What Is It and How Do You Define It?

In the sophoware world, the iteration cycles are quite short. You can push cod to your cur tyour repo and have it go live with in seconds. I think hard tack companies can't. They either have a hardware in the mix, which kind of is not at that same speed yet. Or you might be regulatory, regulatorly constrained. These are all like there's external processes that you can't control effect their iteration cycle time.