We live in a world of ever-increasing data, complexity, and computer intelligence. We are constantly making decisions on how to make software processes faster, more efficient, or cheaper to operate. There is a lot of misguided wisdom, folklore, and superstition around software performance that can be as much help as hindrance. In our tutorial, we'll present some fundamental rules of software performance as a set of physical, intuitive "laws", with illustrative examples. Our goal is for every audience member to leave with enough of a grounding in these underlying laws to make rational performance decisions when selecting their programming tools, algorithms, and hardware. Audience: This tutorial is intended for audiences without a computer science background, or those with a computer science background who are interested in discussing and explaining performance concepts to those without it. Some programming experience in Python will be helpful, as will access to the tutorial notebooks and the ability to run them live. Mathematics will be discussed, but will not be required beyond a high school level to understand and engage.