Full-stack JavaScript was sold as paradise—one language, shared code, happy devs. But this takedown reveals the brutal tax: performance lags, security nightmares, and who's really cashing in.
Slow APIs kill user retention—your app's 3-second lag could be costing thousands in churn. One engineer's Redis caching fix delivered 2x speedups, proving caching's must-have edge in production.
Averages lie. Your backend's p99 latency tells the real story—and it's probably worse than you think. Here's the data-driven playbook to fix it.