Registrar APIs and DNS Interfaces Serve Distinct Roles in Tenant Domain Migrations

When migrating tenant subdomains on a gaming platform, registrar APIs and DNS interfaces handle fundamentally different responsibilities despite both involving domains. Registrar APIs govern domain ownership, nameserver delegation, and transfer state, while DNS interfaces manage individual zone records like A, AAAA, and CNAME entries. Mixing the two workflows risks dangerous race conditions, such as record updates succeeding in an old zone while the application already queries the new one. Best practice involves dual-publishing records in both zones, lowering TTLs in advance, and switching delegation only after verifying answers across authoritative servers, recursive resolvers, and client hostnames. Rolling back should restore delegation rather than delete tenant records, and migration state should be tracked as structured data with phase, target, and observed-answer fields.