🚀 What I built A production-ready cache stampede prevention library in Go with 3 strategies, full Prometheus metrics, and a live Grafana dashboard. 🔥 The problem When a hot cache key expires, thousands of concurrent requests all miss at the same time and hammer the database. This is a cache stampede — and it can take down your DB. 🛡️ 3 strategies implemented Hard Lock + Stale-While-Revalidate Only one process fetches the new value (Redis SETNX + Lua atomic script) Everyone else gets served the stale value immediately — zero wait time 2, XFetch (probabilistic early refresh) Formula: P = exp(-β × timeRemaining / δ) Starts refreshing in the background before the key expires No thundering herd because refreshes are spread out probabilistically Request Coalescing (singleflight) In-process deduplication: 50 concurrent goroutines → 1 real DB call ~13:1 dedup ratio visible in Grafana 📊 Monitoring stack Prometheus metrics for every decision point (hit/miss/stale/lock_contention) Grafana dashboard with 9 panels…