Grab's service mesh evolution: From Consul to Istio

This post details Grab's migration from Consul to Istio for its service mesh. Key technical contributions include designing a resilient architecture with multiple external control planes on dedicated Kubernetes clusters for high availability and isolation, supporting both HTTP and gRPC traffic across multi-cloud (GCP to AWS) and multi-organization environments. The migration involved careful planning for gradual traffic shifting, quick rollback mechanisms, and maintaining service continuity. Lessons learned emphasize questioning assumptions, balancing innovation with stability, and adapting to changing needs.