The Great Sidecar Debate#

William Morgan, Buoyant — Core

• Why: The sidecar-vs-sidecarless architectural question is the central fault line in service mesh right now (Istio ambient, Cilium mesh, Kmesh below); this is a maintainer-level, engineering-tradeoffs framing rather than a vendor pitch for one side.
• What: A pragmatic evaluation of sidecar vs. sidecarless (ambient/eBPF) service mesh architectures across resource consumption, operational blast radius, and security threat models. (from abstract only)
• How: Frames every architectural choice as a tradeoff and works through concrete scenarios where sidecars still win versus where ambient/eBPF approaches are strictly better. (from abstract only)
• Where applicable: General service mesh architecture decisions; useful as a mental framework regardless of which mesh implementation you're evaluating.