Slack's engineering team describes Shipyard, their next-generation EC2 platform built around immutable infrastructure principles. Rather than continuously updating long-lived instances with Chef, Shipyard treats EC2 instances as deployable artifacts using layered AMIs. A shared 'slack-zero' golden base image provides OS hardening, networking, monitoring, and security agents, while service teams build on top of it. AWS Image Builder replaces Packer for baking images, with EventBridge and Lambda triggering downstream pipelines automatically. Deployments use progressive rollouts via Gondola, their internal orchestrator, with metrics-based automated rollback. A component called The Reaper enforces instance lifecycle by replacing tainted or aged instances. An inventory system called Peekaboo provides real-time fleet visibility via AWS EventBridge, OpenSearch, and Lambda. The platform also includes Ship Quick, a developer testing workflow that validates cookbook changes on real infrastructure before merging. Secrets remain dynamic via Consul Template and Vault, making the system semi-immutable. Future work targets long-lived instances like data nodes and singleton services.
