Build a compliant participant recruitment database

WHAT THIS TESTS The interviewer wants to see that you can implement privacy regulation as concrete data structures and workflows, not vague intentions, since a participant database holds sensitive personal data with strict legal obligations.

A GOOD ANSWER COVERS For consent, model it as first-class data: store granular, purpose-specific consents (recruitment, recording, future contact) each with a timestamp, the policy version agreed to, and the lawful basis under GDPR. Make withdrawal as easy as granting, and never bundle unrelated purposes into one checkbox. For storage, apply data minimization by collecting only fields you need, encrypt in transit and at rest, separate direct identifiers from study responses so each is independently controllable, and set retention periods with automated expiry rather than keeping records indefinitely. Enforce role-based access and audit logging. For deletion and other rights, build a verified request workflow that authenticates the requester, then cascades erasure across the primary store, derived datasets, and any processors, with a defined approach to backups, and records that the request was fulfilled within the legal window.

COMMON WRONG ANSWERS A single all-or-nothing consent checkbox with no record of version or purpose. Keeping participant data forever for convenience. Treating a deletion request as a one-off manual edit that misses copies in analytics, exports, and backups. Ignoring that CCPA adds opt-out of sale and access rights distinct from GDPR.

LIKELY FOLLOW-UPS How do you handle deletion in immutable backups. How do consent versions interact when your policy changes. What is a data processing agreement with a recruitment vendor. How do GDPR and CCPA differ on opt-in versus opt-out.

ONE CONCRETE EXAMPLE The database has a participants table holding minimal contact info, a separate consents table with rows per purpose, version, and timestamp, and a study_data store keyed by pseudonym. A deletion request triggers a job that removes the participant and consent rows, anonymizes or deletes linked study data, notifies the recruitment vendor processor, and writes an audit entry with the completion date.