Master Production Ready Testing in Only One Course

... the only thing standing between you and senior developer roles.

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Stop gambling with every deployment.

Here's a little known fact.

Only 1 in 4 Next.js developers write production-ready tests.

The other 3? They deploy and pray.

So who’s the one? What companies do they work for?
Take a look.

The best devs have already realized they need to test their apps or get left behind.

Here's the catch.

My team and I and these massive companies don't just write tests.
We write tests that actually catch bugs.

If you try testing Next.js 16 like plain React, you'll write weak tests that break with every refactor and miss the real bugs.

That's because you're taught that...

"Testing is just writing a few unit tests"

Wrong. Testing is an iceberg.

You think you know it because you only see the 15% of it that’s above water.

So you write some tests. Get 80% coverage. Feel safe.

Like the Titanic hitting an iceberg that seemed tiny, what you skip testing sinks you.

The same thing happened to me.

I was looking for a good way to learn testing for a long time, but I couldn’t find anything.

Every tutorial I came across was basic. It didn’t teach me production patterns.

Most of the people teaching testing have no experience maintaining test suites for massive apps in prod - so they give superficial advice (if the advice is up to date at all).

You don't want to read the never-ending docs or 7,153 articles to learn it all.

So I spent 9 months deep into testing.

Building massive 5 and 6-figure apps with comprehensive test suites.

Testing real production features - authentication, databases, AI integrations.

Rebuilding test architectures from scratch for apps that had zero test coverage.

After all this? I kept getting daily requests to make a testing course. I’m finally doing it.

Here’s a three-part testing method so you don’t have to struggle.

1. Deep dive & understand how testing actually works

Just knowing how to write a test isn't enough.

Not with tests that break every refactor. Not with 90% coverage that still misses bugs.

See, actually understanding testing strategy makes you future-proof.

You'll be able to test any feature - from authentication to AI integrations - and build a well-architected test suite instead of getting overwhelmed.

Here's a little demo of our deep dive lectures:

2.Test and validate complex app

If you only test a small application?

You have a terrible safety net.

That's why basic tutorials, toy examples, and docs aren't enough. How do you actually test server actions, API route handlers, database transactions, and AI integrations all together?

How do you mock external APIs, handle async operations, test authentication middleware, and validate form submissions in production scenarios?

That's what separates a great developer from the mediocre junior who ships bugs to production.

And finally...

3. Active Testing Challenges so you're 100% confident you can test it yourself

Look. The biggest issue with project-based tutorials is that people sometimes just follow along.

You need to write tests yourself because no one will test your production app for you.

This is why I added Active Testing Challenges.

Here you test the most critical parts of the app. You master the testing patterns and walk away with the skills to ship bulletproof apps on your own, guaranteed.

Here's what these challenges look like.

🥁 And the app you'll test is...

A modern StackOverflow clone.

Not a todo app or basic blog that every dev tests in their portfolio 💤

Nope.

The DevOverflow app has all the important features:

Authentication testing (no one teaches this properly)
Server action testing with database operations
AI integration testing with edge cases & so much more

"Okay okay, you convinced me. "

Take me to the pricing section!

Master the leading testing stack for 2025 and beyond

You'll need intermediate knowledge of JavaScript (eg. array methods, async/await, try catch...) and beginner knowledge of React and Next.js (components, server actions, API routes) to take the course.

If you're unfamiliar with these, don't worry. We'll provide you the resources to get you up to speed, but it definitely won't be as easy as if you had experience beforehand.

If you're asking if you need to know testing - you don't. Here at JSM we learn by building comprehensive test suites & this is the perfect chance to learn it since testing is required in most industry projects.

38,596 developers learned Next.js with us.

Here's what they've been asking for since day one.

For 2 years, the same message kept coming:

"I built the app from your course. It's amazing. But... how do I test it?"

"I got the job because of your Next.js course. Now they want me to write tests. Help."

"I can build anything now. But I'm scared to deploy it. Teach me testing."

This course is the answer.

They learned to build. Now they're learning to ship with confidence .

Omar Hassan
Senior Developer at Tech Startup
I used to deploy on Friday and spend the entire weekend fixing bugs. My wife hated it. My manager questioned my code quality. After learning testing, I deploy confidently any day of the week. My pull requests get approved faster. I got promoted to senior developer. And I actually have weekends now.
Sarah Rodriguez
Full Stack Developer
I failed three technical interviews because I couldn't answer testing questions. I could build the feature, but when they asked 'how would you test this?' I froze. After this course, I aced the testing portion of my interview at a Series B startup. They specifically mentioned my testing knowledge as a reason they hired me. Now I'm making $40k more than my last job.
Ahmed Al-Mansoori
Freelance Developer
Clients stopped trusting me. Every deployment broke something. They'd call me angry. I'd fix bugs for free just to keep them from leaving bad reviews. Learning testing changed everything. Now I deliver bulletproof apps. My clients refer me to others. I raised my rates by 50% because I'm worth it. Testing didn't just improve my code - it saved my reputation.
Leila Kassem
Junior to Mid-Level Developer
I was stuck as a junior developer for 2 years. Every code review came back with 'where are the tests?' I didn't know how to write them. I'd google, get confused, and just skip testing. My senior developer finally told me: 'You'll never advance without testing skills.' That hurt. But it was true. After mastering testing, I led my first major feature with full test coverage. Six months later, I got promoted to mid-level with a 30% raise.
Daniel Brooks
Backend Developer at Fintech Startup
Production bugs used to haunt me. Every alert felt like a heart attack waiting to happen. I thought testing would slow me down, but it actually made me faster. Now, my test suite catches issues before they ever reach production. Our CTO even mentioned my reliability in my performance review. Testing became my secret weapon for peace of mind and promotions.
Priya Nair
Frontend Engineer at SaaS Startup
I used to dread refactoring. Every small change felt like defusing a bomb — one wrong move and the UI would break somewhere I didn’t expect. I’d spend hours manually checking pages. After learning testing, I finally trust my code. Now I refactor without fear, ship faster, and my QA team barely finds issues anymore.