Product Market Fit

Product Market Fit

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The Problems That Inspired the World’s Biggest Startups + 15 Problems you can build a company around in 2026 (with AI)

Guillermo Flor's avatar
Guillermo Flor
Jan 24, 2026
∙ Paid

Most people study solutions.

Great founders study problems.

How Airbnb Founders Sold Cereal to Keep Their Dream Alive | by Kenji  Explains | Entrepreneurship Handbook

Airbnb didn’t start with “let’s build a marketplace for short-term rentals.”
Stripe didn’t start with “let’s build payments infrastructure.”
OpenAI didn’t start with “let’s ship a chatbot.”

They all started with something much more primitive:

“This is broken. And nobody has fixed it properly.”

In this piece, I’ll do two things:

  1. Break down the core problems that inspired some of the biggest tech companies in the world (Airbnb, Stripe, Amazon, OpenAI)

  2. Share 15 unsolved problems that I believe can still produce decacorns heading into 2026

If you’re a founder, this is how you should be training your brain.

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Part I – The Problems Behind Iconic Startups

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