Doctor Market Fit

Ultimate Guide to Interviews #4: Don't just ask for problems

How to get deep insights surrounding problems

Dec 4 • 

Jeroen Coelen

5

1

November 2025

Doubt is the goldmine

Embrace uncertainty to increase momentum

Nov 26 • 

Jeroen Coelen

11

3

2

Timing product launches, when to target corporate clients, and getting quality feedback

Three breakdowns of advice I gave last week

Nov 19 • 

Jeroen Coelen

12

3

2

Why potential customers won't switch to your solution

Explained in two simple infographics, and what to do instead

Nov 12 • 

Jeroen Coelen

19

3

4

5 reasons AI startups fail to find product-market fit

Lessons from working founders in the AI gold rush

Nov 5 • 

Jeroen Coelen

7

4

2

October 2025

Ultimate Guide to Interviews #3: Framing the interview

Dozens of outreach message examples, 7 frames for an interview, and do's and don'ts.

Oct 29 • 

Jeroen Coelen

4

4

Ultimate Guide to Interviews #2: Structuring and starting the interview

How to keep your baby in your bag?

Oct 22 • 

Jeroen Coelen

13

1

Ultimate Guide to Interviews #1: Build a customer theory

Take off your founder hat, put on your anthropologist hat

Oct 15 • 

Jeroen Coelen

14

1

To vibecode or not to vibecode?

How to test your idea before you waste weeks vibecoding

Oct 8 • 

Jeroen Coelen

11

8

3

Why I’m against obsessing over measuring too early

Know the difference between design and validation

Oct 1 • 

Jeroen Coelen

12

3

2

September 2025

Here’s what B2B sales taught me about B2B sales

12 quick tips and tactics.

Sep 24 • 

Jeroen Coelen

24

10

1

The Problem Impact Matrix

Are you chasing the right problem?

Sep 17 • 

Jeroen Coelen

30

9

6