Power BI interview questions

12 questions with answers, grouped by topic.

Foundations

The three engines inside Power BI and how they fit together.

1

When would you use DirectQuery instead of Import?intermediate

Power Query

Getting data in and shaping it before it reaches the model.

1

What is query folding and why does it matter?intermediate

Data modeling

Star schemas, relationships, and why the model decides everything.

3

What is a star schema and why does Power BI prefer it?intermediate How do you handle a role-playing dimension like Date?advanced Why should you avoid bidirectional cross-filtering?advanced

DAX

From measures to filter context and time intelligence.

3

What is the difference between a measure and a calculated column?beginner What does CALCULATE do?intermediate Explain the difference between ALL, ALLSELECTED and REMOVEFILTERS.advanced

Service & governance

Workspaces, refresh, row-level security, deployment.

4

How do you implement row-level security?advanced What is the difference between USERNAME() and USERPRINCIPALNAME()?intermediate What are the workspace roles and what can each do?beginner What is incremental refresh and when do you need it?intermediate