🧠 *Power BI Interview Questions (With Answers & Scenarios)* Here’s a solid set of advanced Power BI interview question types to prep you for real-world roles: *1. Scenario-Based DAX Question* *Q:* How would you calculate Year-to-Date (YTD) Sales for only "Premium" customers using DAX? *A:* Use `CALCULATE`, `TOTALYTD`, and a filter condition: `CALCULATE(TOTALYTD([Sales], 'Date'[Date]), 'Customer'[Type] = "Premium")` *2. Power Query Transformation Logic* *Q:* A column has dates in `dd-mm-yyyy` and text like “Invalid” mixed. How do you clean it? *A:* - Use “Detect Data Type” - Replace Errors with null - Filter out nulls - Convert column to Date type *3. Data Modeling & Performance Tuning* *Q:* What is a star schema, and why is it better in Power BI? *A:* A star schema uses fact and dimension tables with one-to-many relationships. It improves performance, supports simple DAX, and enables better visuals. *4. Import vs DirectQuery* *Q:* When would you prefer DirectQuery over Import? *A:* When data is too large or needs real-time freshness (e.g., operational dashboards). But it's slower and limited in features. *5. Gateway & RLS Scenario* *Q:* How do you ensure that region managers only see their region’s data? *A:* Set up Row-Level Security (RLS) on the region field and assign users in Power BI Service with their respective roles. ✅ *React ❤️ for more*