Shopify ↔ 3PL inventory sync with alerting

Cartloop builds Shopify apps; this one is internal for a Plus merchant client. Sync inventory between Shopify and their 3PL's janky SOAP API (I wish I were joking), every 15 min, with discrepancy alerts to Slack and a small audit-log UI. Shopify side is GraphQL Admin API — you must have shipped against it before. Tell me which Shopify apps you've built in your first message.