# How an Expired Let's Encrypt Root Certificate Nearly Caused a Shopify Platform Outage

DevFeed: [How an Expired Let's Encrypt Root Certificate Nearly Caused a Shopify Platform Outage](<https://devfeed.tech/articles/that-old-certificate-expired-and-started-an-outage-this-is-what-happened-next-1641.md>)

Original publisher: [Read original article](<https://shopify.engineering/that-old-certificate-expired-and-started-an-outage-this-is-what-happened-next>)

Author: Raphaël Beamonte

Published: 2022-01-12T15:30:02Z

Content type: article

Language: en

Sources: [Shopify Engineering](<https://devfeed.tech/sources/shopify-engineering.md>), [Shopify Engineering - Shopify Engineering](<https://devfeed.tech/sources/shopify-engineering-shopify-engineering.md>)

Topics: [certificates](<https://devfeed.tech/topics/certificates.md>), [distributed-systems](<https://devfeed.tech/topics/distributed-systems.md>), [incident](<https://devfeed.tech/topics/incident.md>), [resiliency](<https://devfeed.tech/topics/resiliency.md>), [Incident response](<https://devfeed.tech/topics/incident-response.md>), [Shopify](<https://devfeed.tech/topics/shopify.md>), [Containers](<https://devfeed.tech/topics/containers.md>)

Tags: [certificates](<https://devfeed.tech/tags/certificates.md>), [containers](<https://devfeed.tech/tags/containers.md>), [distributed](<https://devfeed.tech/tags/distributed.md>), [distributed-systems](<https://devfeed.tech/tags/distributed-systems.md>), [incident](<https://devfeed.tech/tags/incident.md>), [incident-response](<https://devfeed.tech/tags/incident-response.md>), [outage](<https://devfeed.tech/tags/outage.md>), [resiliency](<https://devfeed.tech/tags/resiliency.md>), [shopify](<https://devfeed.tech/tags/shopify.md>)

## AI overview

Shopify describes how the expiration of an old Let's Encrypt root certificate led to certificate errors between services on September 30, 2021. The incident response included locking monolith deployments and investigating containers while the team worked to understand the problem.

## Source excerpt

In distributed systems, there's plenty of occasions for things to go wrong. This is why resiliency and redundancy are important. But no matter the systems you put in place, no matter whether you did or didn't touch your deployments, issues might arise. It makes it critical to acknowledge the near misses: the situations where something could have gone wrong and the situations where something did, but it could have been worse. When was the last time it happened to you?