When I first used these kinds of methods, I described it along those lines to my friend. I told him I felt like I was summoning a demon and that I had to be careful to do the right incantations with the right words and hope that it followed my commands. I was being a little disparaging with the comment because the engineer in me that wants reliability, repeatability, and rock solid testability struggles with something that's so much less under my control.

God bless the people who give large scale demos of apps built on this stuff. It brings me back to the days of doing vulnerability research and exploitation demos, in which no matter how much you harden your exploits, it's easy for something to go wrong and wind up sputtering and sweating in front of an audience.