Data Residency Gaps in AI Deployments Often Lie Beyond Primary Storage

A system can keep its source records in the correct country and still break residency rules, because data is copied during model inference, vector indexing, tracing, evaluation, and backups. Model calls are transfers in their own right, so routing requests to a region outside the intended boundary breaks residency even when storage looks compliant. Vector stores and evaluation sets are derived copies that inherit the same obligations as the source data, yet teams often treat them as minor infrastructure with weaker controls. Logs and traces, which are needed for incident reviews, should be kept within the same boundary, with named access and deliberately chosen retention periods. The article recommends raising residency and vendor questions in the first week of design, when answers are cheap to implement, rather than after the build is complete.