HashiCorp upgrades the PagerDuty way

Between 2022 and 2023, the cloud infrastructure team at PagerDuty had upgraded Nomad 3 times, made numerous changes to Vault, and jumped 6 major versions of Consul in just 6 weeks. And they didn't cause a major outage during or after any of the upgrades. This talk discusses how the cloud infrastructure team plans for and upgrades Nomad, Consul, and Vault with no downtime to their customers or engineering teams. It covers their architecture, upgrade processes, and lessons learned.