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Sreekar Reddy
Sreekar Reddy

Posted on • Originally published at sreekarreddy.com

📝 Logging Explained Like You're 5

Black box recorder for your app

Day 96 of 149

👉 Full deep-dive with code examples


The Black Box Analogy

Airplanes have black boxes that record everything that happens:

  • Every action taken
  • Every system reading
  • Every event

After a crash, investigators know EXACTLY what happened.

Logging is your app's black box!


What Logs Look Like

[Dec 24 10:15:30] INFO  User john@email.com logged in
[Dec 24 10:15:32] INFO  User viewed product #12345
[Dec 24 10:15:45] ERROR Payment failed: Card declined
[Dec 24 10:15:45] INFO  User redirected to payment retry
Enter fullscreen mode Exit fullscreen mode

Every line tells a story!


Log Levels

Level Meaning
DEBUG Developer details
INFO Normal operations
WARN Something concerning
ERROR Something failed
FATAL App can't continue

Why It Matters

Without logs: "Something broke yesterday, no idea what."

With logs: "At 3pm, the database connection failed because..."

Logs are your time machine for debugging!


In One Sentence

Logging records application events so you can understand what happened when things go wrong.


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