What is the best way to do parent-child company hierarchy mapping with Clay before importing to Salesforce?

First, enrich companies in Clay using multiple data sources to get ultimate parent, immediate parent, and subsidiaries data. Use Clearbit for ultimate parent, Apollo for subsidiaries, and FullContact to confirm HQ vs branch locations. Next, run Salesforce lookups to match companies using stable identifiers (domain, LinkedIn URL, exact name + country) and capture existing Account IDs. Set up logic to flag duplicates by domain + company name similarity, then map ParentId relationships ensuring parents are processed before subsidiaries. Finally, use upsert operations to update existing accounts or create new ones with correct hierarchy links, adding null checks and delays between parent/child creation to prevent duplicates.