Your sparring partner on speeddial

Sanity checks, critical feedback, and pep-talks for startup founders—All within minutes.

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Additional brain

"Jeroen is an additional brain. Someone who shares your ambitions, has relevant experience and knowledge, and can provide support at a deeply personal level"

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Julia

Founder of Badge

Learn to think like a startup

"By working with Jeroen, I've learned how to turn big ideas into small experiments. This increased momentum and focus for our startup. We now know what works, without spending 6 months of building it."

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Caroline - Founder of Grape Genius

Mindset shift to the customer

"He helped me to shift my mind away from what I offer to focus on the customer. From supply to demand. This has helped me to sharpen my value proposition immensely"

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Dylan

Founder of Bildung Academy

Hard and honest feedback

"Jeroen doesn't beat around the bush. He highlighted what customer information I missed in a direct way, I immediately knew where to focus. That's the kind of feedback I prefer to hear, cold and early."

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Javier - Founder of Nummary

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10 years

Experience as mentor

352

Early-stage startups worked with

25+

Accelerators worked at

My way of working

Mentoring Subscription - Jeroen as a Service (JAAS 👸)

  • Unlimited DMs

    You can email me or WhatsApp me unlimited questions throughout the week

  • 30 or 60 minutes call time per week

    Quick call, short calls, sometimes you just need a sounding board. Schedule quickly, I'm flexible, only a few days ahead sometimes.

  • Cancel each month

    14 day free refund, no small print

    What we cover in calls

    Some examples of what I cover

    Sanity check on your priorities

    Should you focus on your MVP, outreach or your marketing campaigns? Is funding the right moment for you?

    Outreach messaging optimisation

    How to write a message that converts? I will inspire with ways of moving the conversation forward.

    Customer call tactics

    What is a good interview script? Which questions to ask? How to structure the conversation to land insights and sales

    Sharpen beachhead segment

    Based on your calls and feedback from customers, I help to identify your super specific niche

    Product roadmap critique

    Which features to include, and which not? I'll act as a sounding board to make sure you are not over-engineering your v1.

    Feedback on landing page or pitchdeck

    I've reviewed hundreds of pitch decks and helped with landing page quick fixes for dozens of startups

    Design experiments and pilots

    Will inspire with dozens of examples and critical aspects not to miss.

    Pep talk when you are down

    Building a startup is a rollercoaster. I will share anecdotes and tips how other founders beat the slump.

    Intros to my network

    If I see an opportunity for you to learn from somebody in my network, I'll intro you.

    Our Team

    Have you ever seen them in the same room together? 😏

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    Jeroen the Mentor

    Guiding light

    Jack of all trades: Trained as a designer, ex-founder, ex-product-owner, innovator at corporates and now experienced mentor.

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    Jeroen the Scientist

    Researcher of product-market fit

    My PhD focuses on how early-stage founders design their startup. Fringe insights from academia.

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    Jeroen the Energizer

    Battler of downs

    Doing a startup is a rollercoaster. I've coach founders through hard times, focusing on the upside of things.

    Almost any startup type

  • Consumer hardware & software

    Trained as a product designer, I love tailoring solutions and propositions to consumers. Marketing to consumers is different than businesses. I'll teach you how.

  • B2B

    How to sell to businessess? How to segment a market if there are 4 stakeholders? Having advised many B2B startups, I help you to navigate that maze.

  • B2G (Government)

    Governments are a peculiar customer type. Mandate is scattered, the organisations can seem like an impenetrable fortress. I will help you get there.

  • Deep Tech

    Science based startups or academic founders to find their beachhead market.

  • Pricing for mentoring

    Jeroen as a Service (JAAS 👸)

    30 minutes per week 

    Monthly subscription

    €190

    / month (excl. VAT)

    Schedule free get-to-know

    €380

    / month

    • 30 minute calltime per week

    • Unlimited questions over chat

    • 14 day free refund, no questions asked

    60 minutes per week

    Monthly subscription

    €250

    / month (excl. VAT)

    Schedule free get-to-know

    €500

    / month

    • 60 minute calltime per week

    • Unlimited questions over chat

    • 14 day free refund, no questions asked

    Single session

    Starting from 15 minutes

    €75

    / session

    Book Directly
    • Quick call, schedule immediately

    • No strings attached

    • All questions you wish to have answered

    Schedule a free get-to-know call

    20 minutes, no strings attached

    Get to know + Some Light problem soving

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