Successfully Merging the Work of 1000+ Developers - Shopify

This post details the evolution of Shopify's Merge Queue system from v1 to v2. Merge Queue v2 addresses the problems of Merge Queue v1 by introducing a comment-based interface (replacing a browser extension), ensuring master stays green by running CI on a predictive branch before merging, and improving emergency merge speed. It also introduces a failure-tolerance threshold for flaky tests and optimizes throughput by defining batch sizes for deployments.