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Why we built this

I learned it all on YouTube.
It nearly didn’t work.

The teaching was never the problem. The best explanation of almost anything is already online, free, from someone who does it for a living.

Everything around it was missing. So we didn’t make more videos — we built that.

Four things a playlist can’t give you

01
No order

Fourteen tabs, all of them good, none of them next.

02
No practice

You watch someone else type. It's gone by Thursday.

03
No signal

The video ends the same way whether you understood it or not.

04
No proof

Watch history isn't a credential.

You don’t need another course.

A twelfth introduction to SQL helps nobody. What’s scarce is the sequence, the checkpoint, and a credential that means something.

See what a path looks like

And the creators keep what’s theirs.

Every video plays on YouTube. The view, the watch time and the revenue stay with the person who made it.

If you make the videos

Why the certificate counts

A credential is only worth the checking behind it.

01
Questions come from the teaching

Generated from the transcript. You can't pass by skimming.

02
A real pass bar

Fail a topic, rewatch the clip, retake.

03
Anyone can check

Every certificate links to a public verify page.

coursified.app/verify/CF-8214-KX● Verified
Product Metrics, from first principles
Amara Okafor · taught by Lenny Rachitsky on YouTube · Aug 2026
Modules assessed 6 of 6
Final assessment 34 questions
Pass mark 75%
Scored 82%
Verify a real certificate →

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