---
title: "Resiliency Planning for High-Traffic Events"
description: "Shopify’s preparation for Black Friday Cyber Monday (BFCM) centers on building and maintaining resiliency practices for a high-traffic platform and large development teams. Regular load and stress tests verify required capacity, probe limits, detect regressions, and compare behavior across differently configured shops. Teams document expected user experiences and dependency failure modes in a resiliency matrix, then use game days to test that model against reality, including alerts, paging, operator readiness, and response procedures. Incident analysis treats disruptions as learning opportunities rather than stopping at a single “root cause”; nearer to BFCM, Shopify slows feature and service changes while increasing work on performance, reliability, scale, runbooks, tools, and bottlenecks. The source says these practices support a platform that powered over $5.1 billion in sales."
---

# Resiliency Planning for High-Traffic Events

[Shopify](https://yomu.fyi/company/shopify) · 2023-10-18 · Dec 10, 2020

**Type:** Explainer

## Summary

Shopify’s preparation for Black Friday Cyber Monday (BFCM) centers on building and maintaining resiliency practices for a high-traffic platform and large development teams. Regular load and stress tests verify required capacity, probe limits, detect regressions, and compare behavior across differently configured shops. Teams document expected user experiences and dependency failure modes in a resiliency matrix, then use game days to test that model against reality, including alerts, paging, operator readiness, and response procedures. Incident analysis treats disruptions as learning opportunities rather than stopping at a single “root cause”; nearer to BFCM, Shopify slows feature and service changes while increasing work on performance, reliability, scale, runbooks, tools, and bottlenecks. The source says these practices support a platform that powered over $5.1 billion in sales.

## Context

Black Friday Cyber Monday is Shopify’s annual peak in traffic and merchant reliance, requiring preparation that begins after the event. The work also addresses the risk that documented system models diverge from reality and that incidents may recur when analysis stops at a single root cause.

## Approach / What changed

Shopify combines recurring load and stress tests, a user-centric resiliency matrix, controlled game days, and incident analysis. As BFCM approaches, teams reduce the rate of new service and feature changes and focus more on performance, reliability, scale, runbooks, internal tools, and issues revealed by testing.

## Takeaways

- Repeated load tests can expose regressions at manageable traffic levels before they become outages at higher peaks, and can compare behavior across shops with different themes or configurations.
- A resiliency matrix documents expected user experiences and dependency failure modes; game days then test those assumptions, including automated defenses, alerting, paging, operator readiness, and response procedures.
- Near BFCM, Shopify shifts investment from new services and features toward performance, reliability, scale, more frequent tests and game days, runbook updates, tooling, and bottleneck fixes.

**Tags:** [Incident Response](https://yomu.fyi/topic/incident-response), [Reliability](https://yomu.fyi/topic/reliability), [Scalability](https://yomu.fyi/topic/scalability), [Testing](https://yomu.fyi/topic/testing)

- Source: [Shopify](https://shopify.engineering/resiliency-planning-for-high-traffic-events)
- Source URL: https://shopify.engineering/resiliency-planning-for-high-traffic-events
- Ingested by Yomu: 2026-08-31T01:10:46.503Z

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