0Pricing
Next.js 15 Fullstack (App Router + Server Actions) · Lesson

Monitoring & Error Tracking in Production

Keep your deployed Next.js app healthy with structured logging, error tracking via Sentry, performance analytics, and uptime monitoring.

Monitoring & Error Tracking in Production is a free Next.js 15 Fullstack (App Router + Server Actions) lesson on CoddyKit — lesson 4 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Next.js 15 Fullstack (App Router + Server Actions) learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.

Why Monitor Production?

Once your app is live, you cannot reproduce every user's environment. Monitoring tells you when something breaks, how often, and for whom — so you fix issues before they spread.

The Three Pillars

Observability rests on:

  • Logs: discrete events
  • Metrics: numbers over time (latency, error rate)
  • Traces: the path of a request across services

Structured Logging

Plain text logs are hard to search. Emit structured JSON logs with consistent fields so tools can filter and aggregate them.

console.log(JSON.stringify({
  level: 'error',
  route: '/api/checkout',
  userId: 42,
  msg: 'payment failed'
}));

Installing Sentry

Sentry captures unhandled errors with stack traces and context. The wizard wires it into both server and client.

npx @sentry/wizard@latest -i nextjs

Capturing Errors

Sentry catches uncaught exceptions automatically, but you can also report handled errors with extra context.

import * as Sentry from '@sentry/nextjs';
try {
  await charge();
} catch (e) {
  Sentry.captureException(e, { tags: { feature: 'billing' } });
}

Error Boundaries with error.tsx

An error.tsx file catches render errors in a route segment and shows a fallback instead of a white screen. It is a Client Component.

'use client';
export default function Error({ error, reset }) {
  return <button onClick={reset}>Try again</button>;
}

Performance with Web Vitals

Track real user experience with Core Web Vitals — LCP, CLS, INP. Next.js exposes them through a reporting hook.

export function reportWebVitals(metric) {
  if (metric.name === 'LCP') sendToAnalytics(metric);
}

Vercel Analytics & Speed Insights

On Vercel, the Analytics and Speed Insights packages collect real-world metrics with one component each, no extra config.

import { SpeedInsights } from '@vercel/speed-insights/next';
// render <SpeedInsights /> in your root layout

Uptime Monitoring

An uptime monitor pings a health endpoint at intervals and alerts you if it fails. Expose a lightweight route for this.

// app/api/health/route.ts
export function GET() {
  return Response.json({ status: 'ok' });
}

Setting Up Alerts

Data is useless if no one looks. Configure alerts: notify the team on Slack when error rate spikes or latency crosses a threshold. Alert on symptoms users feel, not noise.

Best Practices

Stay on top of production:

  • Emit structured logs
  • Track errors with Sentry and error.tsx
  • Watch Core Web Vitals
  • Add an uptime check and meaningful alerts

Quick Check

Test your monitoring knowledge.

Recap

You learned to monitor production:

  • Logs, metrics, and traces form observability
  • Use structured logging and Sentry for error tracking
  • Catch render errors with error.tsx
  • Track Web Vitals, add a health endpoint, and set alerts

Now you find and fix problems before users complain.

Frequently asked questions

Is the “Monitoring & Error Tracking in Production” lesson free?

Yes — the full text of “Monitoring & Error Tracking in Production” is free to read here on the web, and the Next.js 15 Fullstack (App Router + Server Actions) course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Next.js 15 Fullstack (App Router + Server Actions) course, upgrade to CoddyKit PRO.

What will I learn in “Monitoring & Error Tracking in Production”?

Keep your deployed Next.js app healthy with structured logging, error tracking via Sentry, performance analytics, and uptime monitoring. You practise Next.js 15 Fullstack (App Router + Server Actions) with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.

Do I need any experience to start Next.js 15 Fullstack (App Router + Server Actions)?

No prior experience is required. Next.js 15 Fullstack (App Router + Server Actions) on CoddyKit is structured for beginners through advanced learners; this is — lesson 4 of 4, so you can start here or from the beginning and move at your own pace.

How long does the “Monitoring & Error Tracking in Production” lesson take?

Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.

Can I write and run code in this Next.js 15 Fullstack (App Router + Server Actions) lesson?

Yes. Every Next.js 15 Fullstack (App Router + Server Actions) lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.

All lessons in this course

  1. Deployment to Vercel
  2. Building a Fullstack App
  3. Project Review & Best Practices
  4. Monitoring & Error Tracking in Production
← Back to Next.js 15 Fullstack (App Router + Server Actions)