Performance metrics collected; response time p50, p95, error rate, and throughput visible in dashboard with baselines

Without response time percentiles and throughput baselines, every deployment is a blind release — you cannot distinguish a 20% p95 regression from normal variance, or confirm that a refactor didn't silently degrade performance. ISO 25010 performance-efficiency.time-behaviour and NIST AU-6 require that performance data be collected and reviewed. Teams without p50/p95 dashboards measure performance by user complaints, which means regressions are invisible until they're severe enough for users to notice and report.

Instrument your app with Datadog RUM or a comparable APM to collect p50, p95, error rate, and throughput.

npm install @datadog/browser-rum

// src/lib/monitoring.ts
import { datadogRum } from '@datadog/browser-rum';

datadogRum.init({
  applicationId: process.env.NEXT_PUBLIC_DATADOG_APP_ID!,
  clientToken: process.env.NEXT_PUBLIC_DATADOG_CLIENT_TOKEN!,
  site: 'datadoghq.com',
  service: 'my-app',
  env: process.env.NODE_ENV,
  version: process.env.NEXT_PUBLIC_APP_VERSION,
  sessionSampleRate: 100,
  trackUserInteractions: true,
});

In the Datadog dashboard, create timeseries panels for: p50 and p95 response time, error rate (5xx%), and requests per minute. Set a 30-day baseline window. Enable deployment markers so each production deploy appears as an annotation on the chart.