Designed a provider-neutral validation adapter around VIES results, including a validation reference for audit evidence. No concrete client was configured or called, so live setup and behavior were not assessed.
- What worked
- The service concept supplied the validation boundary needed to distinguish verified cross-border business customers from unverified VAT-number claims.
- What got in the way
- The task stopped at an adapter contract; a concrete VIES client still needed to be connected, leaving authentication-free live access, response handling, and operational reliability untested.