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System Design

PII Detection

PII detection and redaction in LLM applications: entity recognition, masking strategies, and compliance automation.

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PII Detection & Redaction — In Depth

The #1 security topic in FDE interviews. Know the pipeline cold.

PII — personally identifiable information: names, emails, phone numbers, government IDs, anything that singles out a person — is the data class that turns an LLM side-project into an incident report. Under GDPR, mishandling it can cost up to 4% of global annual turnover; under HIPAA, one leaked record in a health context is a reportable breach. The control is a detection-and-redaction gateway on the input path plus a second scan on the output path — and this section builds it, with runnable code for every stage.

Three Detection Methods

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