The 'premature optimization is evil' myth (2010)
He is refuting a version of &quot;premature optimization is the root of all evil&quot; that I have never heard in practice:<p>&quot;Mostly this quip is used defend sloppy decision-making, or to justify the indefinite deferral of decision-making.&quot;<p>I have never heard it used in this context. Sometimes I&#x27;ve heard it used as a gentle way to suggest to someone that they are going off in the weeds and need to refocus on what they should be focused on, but usually I&#x27;ve just heard it used as it was originally intended by Knuth.<p>Optimization often involves making code less clear, more brittle, or with a more pasta-like organization. Frequently optimization requires writing code that if looked at out of context, doesn&#x27;t make sense or might even look wrong.<p>When these sorts of optimizations need to be made, they should be made only as needed (and documented). It shouldn&#x27;t be done without knowing whether or not a particular code path is even a bottleneck in the first place, and it shouldn&#x27;t be done if speeding up that particular bottleneck wouldn&#x27;t make the software better in any tangible way. That&#x27;s all the phrase means.