How do you design consent and data-retention policy for data that feeds ML training?

Consent and retention decide whether you can legally train on data and how long you keep it. The signal is purpose limitation, granular consent, enforceable TTLs, and a story for deleting data already baked into a model. Here is the answer.

Updated Aug 2026 · Grounded in real Applied AI Engineer interview loops and written to a senior-engineer editorial bar.