eBPF in Production Kubernetes: Ditch Your Sidecars in 2026

How I cut 75GB of sidecar RAM to 12GB using Cilium, Hubble, Pixie, and Tetragon — with zero app code changes. I'm not going to tell you eBPF is the future. It's already the present. The CNCF Observability TAG survey shows 67% of teams running Kubernetes at scale have adopted at least one eBPF-based observability tool in production. If you're not in that 67%, you're paying for it — literally. Here's what convinced me to migrate our cluster. The sidecar tax nobody talks about We were running Istio. Standard setup — Envoy sidecar in every pod, Jaeger for traces, Prometheus scraping everything. Worked fine until our cluster hit 500 pods. Each Envoy proxy consumes approximately 50–150MB RAM baseline, scaling with connection count. For a 500-pod cluster, that's the difference between over 75GB RAM for sidecars versus roughly 12GB for the entire eBPF stack. That's not a rounding error. That's a billing line item. The stack I run today Four tools, all CNCF projects, all production-grade. Ciliu