10 important DAX interview questions Basic DAX Questions 1. What is DAX, and why is it important in Power BI? DAX stands for Data Analysis Expressions—it's the formula language used in Power BI to create custom calculations and aggregations. It’s essential for building advanced analytics beyond simple visualizations. 2. What is the difference between a calculated column and a measure in DAX? A calculated column is row-based and stored in the dataset, while a measure is dynamic and recalculates based on filters in your report. Measures are more memory-efficient for large datasets. 3. Explain the CALCULATE function and how it modifies filter context. CALCULATE is one of the most powerful DAX functions! It allows you to modify filter context by applying new conditions. Example: 👉 CALCULATE(SUM(Sales[Revenue]), Sales[Region] = "East") This filters data to only include sales from the East region. 4. How does the FILTER function work in DAX? Provide an example. FILTER return...