Jim Keller vs Andrej Karpathy

— Two Faces of Technical Genius, and a Story We Relate To

These two live in completely different worlds.
One works with CPUs and silicon,
the other with AI, code, and language.

But if you look closely,
they’ve been asking the same fundamental questions all along.

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1. “What should we build?” vs. “Why are we building this?”

Jim Keller

• Before designing a chip, he asks:
  “Why should this CPU exist?”
• Instead of raw performance numbers,
  he looks at how much it reduces human thinking time

Andrej Karpathy

• Before building a model, he thinks:
  “How should humans use AI to become smarter?”
• He focuses not on technology itself,
  but on expanding human cognition

👉 Relatable moment

When you’ve worked hard but feel it was meaningless,
both of them always checked the “direction” first.

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2. Geniuses Who Hate Complexity

Jim Keller

• Instead of millions of lines of design,
  he looks first at the slowest point (the critical path)
• “Complex designs are almost always wrong.”

Karpathy

• He famously describes AI like this:

  “Deep learning is just function approximation.”

• No mysticism—
  he explains it in language engineers can understand

👉 Relatable moment

As work becomes more complex,
the anxiety that we’re “missing the core” only grows.

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3. They Chose Broken Places Over Comfortable Ones

Jim Keller

• Joined a broken AMD → revived it with Zen
• Entered stagnant organizations to
  ask uncomfortable but necessary questions

Karpathy

• Challenged the illusion of rule-based autonomy
  and pushed for end-to-end learning
• Changed direction despite heavy criticism

👉 Relatable moment

In places that already work well,
real skill is often invisible.

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4. Neither Wanted to Be a Hero

• Jim Keller:

  “I’m not a genius. I just ask good questions.”

• Andrej Karpathy:

  “AI isn’t magic. It’s just code.”

👉 Relatable moment

The truly great rarely feel the need
to decorate themselves.

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5. The Crucial Difference (Which Makes Them Even More Relatable)

Jim Keller’s World

• Power, heat, cost
• A world of physics that cannot lie
• Results are proven in silicon

Karpathy’s World

• A world where the “right answer” keeps changing
• Today’s failure becomes tomorrow’s solution
• You must endure uncertainty

👉 Relatable moment

Some days we crave
certain results,
and other days we survive by believing in possibility.

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6. The Real Message They Leave Us

✔ Technology changes, thinking remains

• Languages, frameworks, and models keep changing
• But how you think protects your career

✔ Direction matters more than speed

• Moving fast matters less than
  knowing where you’re going

✔ If you can’t explain it, you don’t truly understand it

• If you can’t explain it,
  you won’t convince others—or yourself

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One-Sentence Summary

Jim Keller carved thought into silicon,
Andrej Karpathy spread thought through language.

And both ultimately say the same thing:

“Technology is just a tool.
What truly lasts is how you think.”