Shopify’s journey to faster breadth-first GraphQL execution (2026) - Shopify

This post details the development of GraphQL Cardinal, a new breadth-first execution engine for Shopify's GraphQL data layer. It addresses the performance bottlenecks of conventional depth-first traversal in high-cardinality list queries by executing each field once across all objects, rather than once per object. The engine was prototyped and tested, showing up to 15x faster CPU-bound execution and 90% less memory usage compared to depth-first execution, leading to significant end-to-end response time improvements.