Shopify App Database Optimization: What Breaks at Scale and How to Fix It

If your Shopify app runs fine at 500 merchants and starts degrading at 5,000, the database layer is almost always the first thing to crack, not your app server, not your CDN, and not your queue. Here are the five patterns that cause the most production database failures in Shopify apps, and the exact fixes for each. Missing Composite Indexes on shop_id Every table in a multi-tenant Shopify app needs shop_id as the leftmost column in every composite index. A query filtering on shop_id + status...