Universal Principles of Design, Updated and Expanded Third Edition

143 Premature Optimization

Making elements of a design efficient before they are recognized as important or even needed.

Premature optimization is based on an observation by the computer scientist Donald Knuth that programmers often spend significant time optimizing code too early in the development cycle. They expend resources on components that end up playing a trivial role in overall performance or on components that ultimately get cut in the final product.

The intentions behind premature optimization are invariably good — i.e., programmers trying to create efficient code — but the result of such efforts is wasted energy, time, and money. For this reason, Knuth suggests that “small efficiencies” should be ignored 97% of the time and declares ...