What we learned after a year of GitLab.com on Kubernetes

This post details GitLab's year-long effort to migrate GitLab.com services to Kubernetes. It outlines the challenges faced, including increased billing from cross-AZ traffic, managing resource limits and requests for scaling, improving metrics and logging for observability during the transition, and strategies for shifting traffic to the new cluster using a canary stage. The post also discusses the use of Terraform and Helm for managing Kubernetes configuration within GitLab itself, and the lessons learned regarding the importance of detailed log queries, rollback procedures, and combining metrics from legacy VM and Kubernetes environments.