Shipyard: How We Built Slack’s Next-Generation EC2 Platform

This post introduces Shipyard, Slack's next-generation EC2 platform, which shifts from continuous configuration management to an immutable, artifact-based approach for EC2 instances. Key contributions include: the design principles of Shipyard (immutability, progressive rollouts, automated safety), multi-architecture/OS support, metrics-driven deployments with safety controls integrated with Gondola, fast provisioning via layered images (slack-zero base image + service images), simplified configuration management (baked into images, applied during provisioning), real-time fleet visibility via the Peekaboo inventory system (using AWS EventBridge, OpenSearch, Lambda), and short-lived, continuously refreshed instances. It details the use of AWS Image Builder for slack-zero base image creation and the separation of instance preparation into 'baking' and 'provisioning' phases. Deployment strategies using AWS Instance Refresh and Karpenter are also covered.