Interview Guides
At companies like Northstar Analytics, SQL results are often shared directly with stakeholders, so data quality issues can quickly undermine trust. Interviewers ask this question to understand whether you validate your outputs instead of only writing queries that run.
Explain how you ensure the accuracy and integrity of your data before presenting findings. Your answer should cover how you check for missing values, duplicates, invalid records, and aggregation mismatches. Also describe how you confirm that your final numbers align with business definitions and source data.
Keep the discussion practical and SQL-focused. The interviewer is not looking for a full data governance framework; they want a clear workflow you would follow when validating query results, examples of checks you would run, and how you would communicate assumptions or limitations before presenting insights.
