Frontend Performance Monitoring in Practice: A Full-Stack Guide from Core Web Vitals to RUM
Overview No matter how fancy your backend monitoring is, if the user opens the page and sees a blank screen for 5 seconds, your all-green SLOs mean nothing. This isn’t me being contrarian. Many teams have dashboards full of CPU, memory, QPS, and P99 latency metrics, looking perfectly healthy. But real users are already flooding customer support with complaints — “page loads slow,” “can’t click anything,” “images keep jumping around.” Where’s the problem?...