Context

Dashboard queries are common in analytics and data engineering interviews because they test whether you can turn raw data into reliable business metrics. Interviewers want to see that you understand both query logic and data quality considerations.

Question

Explain how you would use SQL to prepare data for a dashboard. In your answer, describe how you would:

1. Filter and clean raw records
2. Aggregate data to the right reporting grain
3. Handle missing or duplicate values
4. Structure output for common dashboard metrics such as daily totals, counts, or averages

Scope Guidance

Keep the discussion practical and SQL-focused. You do not need to design a full BI system, but you should explain the main steps, common SQL patterns, and how you would make the output reliable and easy for a dashboard to consume.