17.12Better interview wording

“I'd identify the dependency first: Contacts require the Account relationship, so I wouldn't parallelize those operations blindly. I'd upsert the Account by external ID, capture the resulting Salesforce ID, then transform and upsert the Contacts as a collection. I'd also explicitly define partial-failure semantics because an Account write that already committed cannot simply be rolled back when a later Contact write fails.”

Excellent.