I built a network failure simulator in a single HTML file

I wanted a tool to run NOC failure drills without setting up a lab. Everything I found was either too heavy or required a server. So I built Simvex. What it does Simulates link failures and automatic rerouting Connects to RIPE Atlas API for real latency data ML anomaly detection (EMA Z-score + cooldown) Load any topology via JSON Export PDF reports, CSV, SVG, JSON topology Zero install — single HTML file, open in browser The interesting parts Particles without re-creating DOM nodes The traffic animation initially called remove() and enter() every second. At scale it was slow. Fixed by building the array once and only calling .attr() on existing elements each step. ML without spam Raw Z-score on noisy latency data fires alerts constantly. Added EMA smoothing (α=0.3) before the Z-score calculation, plus a 5-step cooldown between alerts. Alert spam dropped to zero. Resize without rebuilding the map Used ResizeObserver on the container — when size changes, repositionSvg() recalculates W/H