The request
“Custom variables in the GTM account are a mess. Facebook, Shopify, and GA don't match. Identify why and fix it so we can trust one set of numbers.”
Three sources of truth and none of them agreed.
The approach
We cleaned up the Tag Manager setup, removed duplicate and conflicting triggers, aligned the purchase events across Facebook and Google Analytics, and verified all three matched on test orders.
What we shipped
Tag Manager variables cleaned up
Duplicate triggers removed
Purchase events aligned across platforms
Verified against Shopify orders