Why Was My Frontend So Slow?

So recently my frontend started feeling very slow.

At first, I thought:

• Maybe React needs time to compile.
• Maybe my laptop is slow.
• Maybe it’s a network issue.
• Maybe it’s just my ASUS TUF acting like a jet engine again.

Clicking on any component felt delayed.
Everything responded… but with lag.

For days, I didn’t investigate properly.
I just frustrated myself and blamed the frontend.

And for days I tried to fix it.

Tried many things.
Asked every AI I knew.
Went to Stack Overflow, Reddit, GitHub, YouTube searching for answers like I was trying to find the Infinity Stones.

I never even looked at the backend.

---

The Real Culprit

Later, while debugging something unrelated in the backend, I noticed something interesting.

There were too many console logs.

They were added for debugging purposes. Harmless, right?

Not exactly.

cron.schedule('* * * * *', async () => {
  const users = await User.find({}); // Fetching ALL users 

  users.forEach(user => {
    console.log(`Checking user ${user.id}`); 
    console.log(`Processing subscription for ${user.email}`); 
    console.log(`Status: ${user.status}`);
    
    // ... logic ...
  });
});

(The above code is just an example)

There was a cron job running in the background that scanned the entire database to check subscription expiries.

When that cron job ran:

• It logged heavily.
• It occupied the thread.
• Other incoming requests had to wait.
• The frontend requests got delayed.

And suddenly…

The “slow React frontend” mystery was solved.

• It wasn’t React.
• It wasn’t my laptop.
• It wasn’t the network.

It was excessive logging + blocking backend work.

Lesson Learned

The thing that helps you debug in development can hurt you in production.

Heavy console logging inside long running jobs can:

• Slow down request handling
• Block threads
• Increase response times
• Make the frontend look broken

Now I’m way more careful about:

• Logging levels
• Cron job design
• Async handling
• Production logging strategy

Sometimes the frontend isn’t slow.

It’s just waiting for the backend to breathe.