Power Bi Dax Optimization

This DAX optimization prompt does the heavy lifting of performance analysis that most Power BI developers skip. It systematically checks for expensive context transitions, identifies repeated calculations that should be variables, and flags inefficient function choices like COUNT over COUNTROWS. You feed it a slow DAX formula and get back an optimized version with variables, proper error handling, and clear comments explaining every change. The four-step analysis framework catches both obvious performance killers and subtle maintainability issues that cause problems months later when someone else inherits your measures.