Klaviyo change history: Shopify API Outage

Klaviyo’s major Shopify API outage caused integration setup errors and data-sync delays from 2026-06-03 14:23 UTC to 2026-06-03 17:16 UTC, lasting 2 h 52 min. Klaviyo attributed it to a partial upstream-service outage; syncing returned to normal, with automated retries clearing backlogs and failed integration states. Customers whose new integration setup failed can retry.