Multi-Tenancy and Isolation

When one AI system serves many customers (tenants), the cardinal rule is that no tenant can see another's data, ever. In RAG this means every retrieval is filtered by tenant so the vector search cannot return another tenant's documents; it extends to caches, logs, fine-tunes, and rate limits. The dangerous failure is a cross-tenant leak. Applied-AI interviews probe it because enterprise deployments are multi-tenant, and a leak between customers is a catastrophic, trust-destroying breach.