Doctor Market Fit

To vibecode or not to vibecode?

How to test your idea before you waste weeks vibecoding

Oct 8 • 

Jeroen Coelen

8

4

Why I’m against obsessing over measuring too early

Know the difference between design and validation

Oct 1 • 

Jeroen Coelen

12

3

September 2025

Here’s what B2B sales taught me about B2B sales

12 quick tips and tactics.

Sep 24 • 

Jeroen Coelen

22

9

The Problem Impact Matrix

Are you chasing the right problem?

Sep 17 • 

Jeroen Coelen

30

9

Ultimate Guide: Revenue Models

5 simple steps and a handy cheatsheet

Sep 10 • 

Jeroen Coelen

36

The four hurdles of manual outreach

Tactics to improve your outbound messaging

Sep 3 • 

Jeroen Coelen

32

8

August 2025

Check how close you are to PM-fit with The Startup Thermometer

The simplest framework for visualising product-market fit

Aug 27 • 

Jeroen Coelen

26

Does your landing page pass the five-second rule?

One quick test to see if customers “get it.”

Aug 20 • 

Jeroen Coelen

33

No, AI didn't kill product-market fit

Reviewing five claims about AI and PM-fit

Aug 13 • 

Jeroen Coelen

30

Your sales pitch might be holding back your growth

How this founder changed one thing to unlock traction

Aug 6 • 

Jeroen Coelen

28

For the love of god, stop comparing your startup to Lovable

Its growth is based on four unfair advantages you can’t just copy-paste

Aug 2 • 

Jeroen Coelen

22

July 2025

I recently discovered I’m a hypocrite

My f*ck-up story.

Jul 30 • 

Jeroen Coelen

20

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