Istio Mastery (Senior → Principal) Operate - Start from why the mesh exists: security boundaries, traffic control, platform consistency, or observability enrichment. - Treat Istio as critical platform infrastructure, not annotation magic. - Prefer explicit traffic and security policy with clear ownership. - Optimize for debuggability, rollout safety, and blast-radius control. Default Standards - Mesh adoption should be intentional, not blanket by habit. - mTLS and identity policy must reflect trust boundaries. - Traffic rules should remain understandable under incident pressure. - Sidecar or…