When your profiler swears everything’s fast but your metrics are screaming bloody murder eBPF From Rust: The 34ms Ghost We Couldn’t See When your profiler swears everything’s fast but your metrics are screaming bloody murder eBPF provides kernel-depth observability without overhead — tracing from userspace through syscalls to kernel internals reveals bottlenecks invisible to traditional profilers. So here’s the thing that drove us absolutely insane for three weeks straight. Our API had this… ceiling. Like we’d hit an invisible wall at 84ms P99 latency and nothing — and I mean nothing — we tried could push through it. The really maddening part? Every profiler we threw at it said we were doing great. Database queries? Lightning fast. Network calls? Barely a blip. Application code? Optimized to hell and back. But somehow, somewhere, 34 milliseconds were just… vanishing into thin air.…