Monitoring and Error Tracking

Here's a question every app builder should answer:

If your app crashes at 3 AM, how will you find out?

If the answer is "a user will email me," you have a problem. By the time users are emailing you, they've already had a bad experience — and some of them have already left.

Monitoring and error tracking are how you know what's happening with your app when you're not looking at it.

Why Monitoring Matters

Without Monitoring	With Monitoring
Users tell you something is broken	You know before users notice
You guess what went wrong	You see exactly what happened
You spend hours reproducing bugs	You have the error details immediately
You don't know if your app is slow	You see performance trends
You find out about problems randomly	You get alerted automatically

Two Types of Monitoring

1. Error Tracking

Error tracking captures detailed information when something goes wrong in your app:

What error occurred
Where in the code it happened
What the user was doing
What browser/device they were using
What data was involved
How many users were affected

Think of it as a black box recorder for your app.

2. Uptime Monitoring

Uptime monitoring checks whether your app is accessible and responding correctly:

Is the server reachable?
Does the homepage load?
Are API endpoints responding?
Is the database connected?
Is the SSL certificate valid?

Think of it as a smoke detector for your app.

What to Monitor

Critical: Monitor These From Day One

What	Why	Tool Example
App crashes	Know immediately when something breaks	Sentry
Server uptime	Know when your app goes offline	Uptime Robot
API errors	Catch backend failures	Sentry
Database connectivity	Detect database issues early	Server monitoring

Important: Add These as You Grow

What	Why	Tool Example
Page load time	Catch performance issues	Google Analytics
User sign-ups	Track growth and spot registration issues	Analytics
Failed logins	Detect brute force attacks	Custom logging
Slow queries	Find database performance problems	Database monitoring
Server resources	CPU, memory, disk usage	Server monitoring

Nice to Have: For Mature Apps

What	Why
User behavior analytics	Understand how users interact with your app
Business metrics	Revenue, conversion rates, churn
Custom dashboards	Combine all metrics in one view

Free Monitoring Tools to Start With

You don't need an expensive enterprise solution. These free tiers are enough for most small apps:

Tool	What It Monitors	Free Tier
Sentry	Error tracking	5,000 events/month
Uptime Robot	Uptime monitoring	50 monitors, 5-minute checks
Better Stack	Uptime + status pages	10 monitors, 3-minute checks
Google Analytics	User behavior, performance	Unlimited
Logtail	Log management	1GB/month
Healthchecks.io	Cron job monitoring	20 checks

How to Set Up Error Tracking

Go to sentry.io and create a free account. Sentry is the industry standard for error tracking and has a generous free tier.

Step 2: Install Sentry in Your App

Ask your AI tool to add Sentry to your project:

Add Sentry error tracking to my [framework] app.

Requirements:
- Install the Sentry SDK for [framework/language]
- Initialize Sentry with my DSN (stored in environment variable SENTRY_DSN)
- Capture unhandled exceptions automatically
- Set up source maps for readable stack traces
- Include user context (user ID if logged in)
- Set environment to production/staging based on NODE_ENV
- Do not send errors in development mode

Step 3: Test It

Trigger an intentional error in your app and verify it appears in Sentry's dashboard.

Step 4: Set Up Alerts

Configure Sentry to notify you when:

A new error type appears
An existing error increases in frequency
An error affects more than X users

How to Set Up Uptime Monitoring

Go to uptimerobot.com and create a free account.

Step 2: Add Your App URL

Add a monitor for your app's URL. Set it to check every 5 minutes.

Step 3: Add Key Endpoints

Monitor more than just your homepage:

https://yourapp.com/ — homepage
https://yourapp.com/api/health — API health endpoint (if you have one)
https://yourapp.com/login — login page

Step 4: Set Up Notifications

Configure alerts via:

Email
SMS (paid plans)
Slack / Discord / Telegram webhooks

What to Do When You Get an Alert

Error Alert

Don't panic. Errors happen. You have monitoring precisely so you can catch them calmly.
Check Sentry for the full error details — stack trace, user context, environment.
Reproduce the issue if possible. Try to understand what the user was doing.
Fix the bug — use AI to help, but review the fix carefully.
Deploy the fix following your deployment process.
Verify the error stops appearing in Sentry.
Document what happened and how it was fixed.

Uptime Alert

Check if you can access the app from your browser.
Check your hosting provider's status page — they may have an outage.
Check server resources — CPU, memory, disk (if you have server monitoring).
Restart the app if needed.
Investigate the cause after restoring service.
Document what happened and how to prevent it.

The Monitoring Checklist

The Bottom Line

You can't fix what you don't know is broken.

Monitoring and error tracking are not optional extras. They are the minimum requirement for running a professional application. Set them up before you launch, not after your first user reports a problem.

The free tiers of Sentry and Uptime Robot are enough for most small apps. There's no excuse not to have them.

Why Monitoring Matters​

Two Types of Monitoring​

1. Error Tracking​

2. Uptime Monitoring​

What to Monitor​

Critical: Monitor These From Day One​

Important: Add These as You Grow​

Nice to Have: For Mature Apps​

Free Monitoring Tools to Start With​

How to Set Up Error Tracking​

Step 1: Sign Up for Sentry​

Step 2: Install Sentry in Your App​

Step 3: Test It​

Step 4: Set Up Alerts​

How to Set Up Uptime Monitoring​

Step 1: Sign Up for Uptime Robot​

Step 2: Add Your App URL​

Step 3: Add Key Endpoints​

Step 4: Set Up Notifications​

What to Do When You Get an Alert​

Error Alert​

Uptime Alert​

The Monitoring Checklist​

The Bottom Line​