Interview Guides
Clean input data is critical before you analyze BMW Group campaign performance in tools such as BMW Group Adobe Analytics dashboards or CRM reporting. Interviewers usually want to hear how you make raw data reliable before any KPI or audience analysis.
Explain how you approach data cleaning and preparation in SQL. Walk through how you would inspect a raw marketing table, identify bad or inconsistent values, handle NULLs, standardize text fields, remove duplicates, and prepare a trusted dataset for downstream reporting.
Keep your answer practical and SQL-focused. You should describe the sequence of checks you would run, the PostgreSQL techniques you would use, and how you would balance correctness, reproducibility, and auditability rather than giving only high-level data quality principles.
