8.9Key Takeaways

• Data masking is a legal requirement (GDPR, HIPAA, PCI DSS), not just a best practice
• Masked data must preserve format, relationships, and referential integrity
• Masking must be irreversible — no way to recover original data
• Test masking quality: format, consistency, referential integrity, irreversibility
• GDPR right to erasure requires testing that deletion removes ALL references across ALL tables

Interview Talking Point: "I use SQL as a verification layer in my test automation — after an API call creates a record, I query the database to confirm data was persisted with the right defaults and constraints. I am comfortable with JOINs, GROUP BY, subqueries, and transaction-based test data management. I also test database migrations separately: apply, verify data integrity, roll back, and verify again. For NoSQL stores like Redis and MongoDB, I test TTL behavior, document structure, and cache invalidation."