pii

Zero retention, private endpoints, redaction pipelines, or open weights in their VPC, the four-rung ladder for PII-sensitive deployments, and the discovery questions that pick the right rung.

Fifty milliseconds at p99 to catch toxicity, PII, and injection on every message. An LLM in the hot path blows the budget. The strong answer tiers the checks and keeps the LLM off the critical path.

A deceptively simple screener: each detection method maps to a PII class, and the 'why not regex for names' sub-question has a precise answer about structure vs context that interviewers use as the pass bar.

An architecture question with a defensible right answer, and interviewers are tired of 'it depends.' Here's the split that survives both the platform team's consistency argument and the app team's context argument.

The four-point redaction design is becoming the standard FDE privacy round. Most candidates fortify the chat box and lose on the other three doors, here's the full design, including the de-redaction map that makes it usable.