Data Quality & Troubleshooting Missing/Incorrect Data Questions

Understand how to identify and troubleshoot data quality issues. Common issues: (1) Duplicate records—same person appears multiple times in database, (2) Missing data—required fields are blank, (3) Incorrect data—email addresses formatted inconsistently, (4) Out-of-sync data—CRM and analytics show different numbers, (5) Tracking failures—events not being recorded. When investigating data quality issues: (1) What specifically is wrong? (2) How much data is affected? (3) When did it start? (4) What changed around that time? (5) What's the impact? (6) How do we fix it going forward? Example: 'Our lead count from website forms dropped 30% overnight. I checked: Was form code broken? (no) Were people still submitting? (yes) Were submissions being captured? (no—tracked in analytics but not reaching CRM) Root cause: API integration failed. We manually synced overnight data and fixed the API.' For junior level, show you think systematically about investigating issues and involve technical teams when needed.