Most code I’ve seen is written in an environment where people can’t afford to “intuit”: thinking through the repercussions of specific language or algorithm choices comes second to solving a problem “well enough”. Building an intuition takes learning how you’ve built something poorly, and for a specific problem can take hours to gain context and walk yourself through many paths.

Bring in a performance expert and their intuition can quickly identify many performance improvements. The tough part for the business is when and where do you pay for the experience of performant code, and when is good enough to leave alone?