How we prepare Shopify for BFCM (2025) - Shopify

This post details Shopify's comprehensive BFCM (Black Friday Cyber Monday) readiness program for 2025, focusing on year-round resilience building, Game Days (chaos engineering at scale), load testing, and scale testing. It highlights the challenges of preparing new infrastructure for peak traffic, the systematic approach to identifying and fixing bottlenecks (e.g., Kafka partition increases, API memory optimization, connection timeout tuning), and the integration of these efforts into a permanent operational plan. The post emphasizes the scale of testing, including simulating regional failovers and coordinating with external providers like YouTube, and the iterative process of fixing issues identified across multiple scale tests. It also touches on the importance of cross-team coordination and the development of permanent infrastructure improvements like the Resiliency Matrix and Critical Journey Game Days.