Hey there 👋
Picture this: It's 2 AM. You're sleeping peacefully.
Meanwhile, your SaaS app is throwing errors for 200+ users, and you have no idea.
You wake up to angry emails, support tickets, and maybe a few cancelled subscriptions.
Fun times, right?
I get messages from indie hackers asking:
- How do I know when my app breaks?
- Why can't I reproduce user-reported bugs?
- How to fix issues before they become disasters?
...and about 73 more monitoring questions.
Let me show you how to sleep better at night while keeping your users happy.
Why Monitoring Matters (Even Early On)
Meet Jake.
Jake built a really cool invoice generator SaaS.
Everything worked perfectly on his MacBook.
He launched, got his first 50 paying customers, and felt great.
Then disaster struck.
- Week 2: Users started complaining about "random errors" when generating PDFs.
- Week 3: Payment processing failed for users in Europe (timezone issues).
- Week 4: A silent database connection leak caused his app to crash every few hours.
Jake lost 40% of his customers before he even knew there were problems.
"It Works on My Machine" Isn't Good Enough
Your local development environment is perfect:
- Fast internet connection
- Latest browser
- No ad blockers
- Perfect data
- Single user (you)
Production is chaos:
- Slow mobile connections
- Old browsers with weird quirks
- Browser extensions that break JavaScript
- Unexpected user behavior
- Multiple concurrent users
- Third-party service outages
Building User Trust
Users don't expect perfection, but they expect transparency and quick fixes.
Bad:
User reports bug → You ask for details → You try to reproduce → Maybe fix it in a week
Good:
Error happens → You get notified instantly → You fix it → You tell the user it's resolved
The second approach builds . The first one builds .
What Sentry Is and Why It's Great for SaaS Devs
Sentry is like having a 24/7 security guard for your app who:
- Catches every error that happens
- Takes detailed notes about what went wrong
- Immediately calls you when something breaks
- Helps you understand why it broke
Real-Time Error Tracking with Context
When an error happens, Sentry captures:
- Stack trace: Exactly where the code broke
- User context: Who experienced the error
- Environment details: Browser, OS, device info
- Breadcrumbs: What the user did before the error
- Release information: Which version caused the issue
Full-Stack Support
Sentry works with everything:
- Frontend: React, Vue, vanilla JavaScript and more
- Backend: Node.js, Python, Go, PHP and more
- Mobile: React Native, Flutter, native iOS/Android, and more
- Frameworks: Next.js, Express, Fastify and more
Instant Alerts
Get notified via:
- Email (basic)
- Slack (recommended)
- Discord
- Webhook to any service
- Mobile push notifications
No more discovering bugs days later.
Installing Sentry in Your Stack (Quick Setup)
Step 1: Create Your Sentry Project
- Sign up at sentry.io (free tier is generous)
- Create a new project
- Choose your platform (Next.js, Node.js, etc.)
- Copy your DSN (Data Source Name)
Step 2: Next.js Setup
npx @sentry/wizard -i nextjs
The wizard creates all the necessary files automatically:
- sentry.client.config.js
- sentry.server.config.js
- sentry.edge.config.js
Step 3: Backend API Setup (if separate)
// server.js
import * as Sentry from "@sentry/node";
Sentry.init({
dsn: process.env.SENTRY_DSN,
environment: process.env.NODE_ENV,
});
// Catch all unhandled errors
app.use(Sentry.Handlers.errorHandler());
Step 4: Custom Error Reporting
// Capture custom errors
try {
await processPayment(userId, amount);
} catch (error) {
Sentry.captureException(error, {
tags: {
section: 'payment',
userId: userId
},
extra: {
amount: amount,
paymentMethod: paymentMethod
}
});
throw error;
}
That's it. Your app is now monitored.
How to Handle and Fix Issues Fast
Reading Stack Traces Like a Pro
When you get a Sentry alert, look for:
- Error Message: What actually broke
- File and Line Number: Exactly where it broke
- Function Name: Which function caused the issue
- User Context: Which user(s) are affected
Prioritizing Critical Errors
🔴 Critical (Fix Immediately):
- Payment processing failures
- User authentication issues
- Data loss or corruption
- App crashes affecting multiple users
🟡 High Priority (Fix Today):
- Feature completely broken for some users
- Performance issues causing timeouts
- Third-party integration failures
🟢 Low Priority (Fix This Week):
- Minor UI glitches
- Edge case errors affecting few users
- Non-critical feature issues
Using Breadcrumbs for Context
Breadcrumbs show what the user did before the error:
- User clicked "Generate Invoice"
- API call to /api/invoices/create
- Database query executed
- PDF generation started
- 💥 Error: "Cannot read property 'address' of undefined"
Now you know: The error happens when customer address is missing during PDF generation.
User Context is Gold
Sentry shows you:
- Which user experienced the error
- Their browser and device info
- Custom context you added (subscription tier, feature flags, etc.)
This helps you understand if it's a specific user issue or a broader problem.
Automating Your Issue Resolution Workflow
Step 1: Set Up Slack Alerts
- Go to your Sentry project settings
- Add Slack integration
- Configure alert rules:
- Critical errors: Instant notification
- New errors: Notify immediately
- Regression: When fixed bugs reappear
Sample Alert Rule:
IF: New error occurs
AND: Affects more than 1 user
THEN: Send Slack notification to #alerts channel
Step 2: Mark Issues as Resolved
When you fix a bug:
- Deploy the fix
- Mark the Sentry issue as "Resolved in next release"
- Add a comment explaining the fix
If the bug reappears, Sentry will reopen the issue and alert you about the regression.
Step 3: Connect to Your Project Management
Optional integrations:
- GitHub Issues: Auto-create issues for new errors
- Linear: Sync bugs with your task management
- Jira: For teams using Jira
Pro tip: Start simple with just Slack alerts. Add complexity later if needed.
Real-World Scenarios
Scenario 1: Silent Payment Failure
What happened:
- User tries to upgrade subscription
- Payment succeeds with Stripe
- Database update fails silently
- User pays but doesn't get upgraded
Without Sentry:
- User complains days later
- You manually investigate
- Hard to reproduce the exact conditions
With Sentry:
- Error captured instantly with full context
- You see exactly which database query failed
- You fix the transaction handling
- You proactively reach out to affected users
: User trusts you more because you fixed it before they even noticed.
Scenario 2: Mobile App Crashes
What happened:
- iOS users on older devices experience crashes
- Happens only with specific screen sizes
- You don't have test devices for every iOS version
With Sentry:
- You see crash reports with device details
- Stack trace points to responsive design issue
- You reproduce on browser dev tools
- Fix deployed within hours
Without Sentry:
- You might never know why you're losing iOS users.
Scenario 3: Third-Party API Outage
What happened:
- Your email service provider has an outage
- User registration emails fail to send
- New users can't verify their accounts
With Sentry:
- Immediate alert about email API failures
- You quickly switch to backup email service
- You identify affected users and resend emails
- You communicate proactively about the issue
: Minimal user impact, professional handling of external issues.
Your Monitoring Action Plan
Basic Setup
Fine-Tuning
Process
Ongoing Habits
- Check Sentry alerts immediately
- Fix critical errors within hours, not days
- Mark issues as resolved when you deploy fixes
- Use error trends to improve your codebase
Remember: You don't need a huge team to build a reliable SaaS.
Tools like Sentry give you superpowers—launch fast, but fix fast too.
Your users will notice the difference between a developer who:
- Discovers bugs when users complain
- Fixes bugs before users even know they exist
The second type builds successful SaaS products.
Start monitoring today. Your future self (and your users) will thank you.
Sleep better, ship better, succeed better 🚀
