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Document anonymization at scale

Legal · training

A large-scale anonymization pipeline for legal documents, producing usable training corpora without exposing personal data or identifying information.

Tech stack

  • Python
  • spaCy
  • Presidio
  • Named Entity Recognition
  • Rules & regex
  • PostgreSQL
  • Batch processing

Data typology

Inventory the entities to mask (names, addresses, numbers, case references) and define consistency rules that keep documents readable.

Hybrid detection

Combine NER models with deterministic rules (regex, dictionaries) to maximize recall on sensitive data.

Consistent anonymization

Stable pseudonym substitution: the same entity gets the same replacement across the whole corpus, preserving meaning.

Quality control

Sample and manually review outputs, measure residual leakage rate, iterate on the rules.

Screenshots

Screenshots coming soon — project under NDA.