Welcome to your interview.
The question is on your right: SQL Indexes, DAX, and Direct Query. Take a moment with it first.
Talk your thinking through with me if you like - when you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes). Discussion and graded submissions share your five interviewer interactions, so spend them well.
Explain the differences between indexes storage on disk, how INTERSECT works, how to use ROW_NUMBER without ORDER BY, sum vs SUMX in DAX, and how to optimize Power BI DirectQuery.