Product-Market Fit Without Guessing

Marc Krejci

Managing Director, Pathfinder Foundry

Real customers. AI agents. The Human-Driven Agentic Flywheel.

Building has never been easier. Validation has never mattered more.

Most early-stage founders are stuck in the same trap: build fast, ship something, wait for traction that doesn't come. Then realize they were solving the wrong problem for the wrong person. The root cause is almost always accountability and process: you know what to do, and nothing is holding you to doing it.

In four weeks, you'll run a complete validation loop end to end using a proven human-driven agentic flywheel: sharpen a real bet, build a clickable prototype with AI agents, put it in front of real customers, synthesize the signal, and make a commit decision backed by evidence.

You leave with a tested prototype and a sent Design Partnership Agreement. AI agents accelerate the synthesis and the building. The conversations with real humans are yours to have. No synthetic shortcut.

Every session is live demonstration, group practice, and a public commit the cohort holds you to.

What you’ll learn

Four weeks of structured practice. Four deliverables. One sent Design Partnership Agreement.

Write a falsifiable hypothesis naming a specific ICP, a specific problem, and what would prove you wrong.
Understand the validation gradient: curiosity, interest, commitment, payment, and why "would you use this?" tells you nothing.
Leave Week 1 with a sharpened bet and confirmed interviews on the calendar, held publicly by the cohort.

Source the right people across three tiers: personal network, social media, and paid channels, in that order.
Run interviews that are 80% listening. No pitching, no leading questions, no "would you use this?"
Build and test a clickable prototype in one session. Put it in front of real customers, not synthetic personas.

Turn messy interview transcripts into one testable conjecture using AI agents in the protovibing.ai canvas.
Score demand intensity: painkiller or vitamin, urgent or merely inconvenient. Only build what people already work hard to solve.
Run a second loop on the evidence, not your gut. Your next prototype prompt comes from the synthesis document, not opinion.

Make the iterate-or-commit decision with evidence, not momentum. Present your case to the cohort.
Draft a Design Partnership Agreement: interaction cadence, feedback type, access terms, and duration.
Investors at pre-seed and seed want to see signed DPAs before writing a check. You leave with one ready to send.

Learn directly from Marc

Marc Krejci

Contact

8-time founder. 7.5 years at Meta. 20+ years of zero-to-one launches.

Built with teams from:

See all products from Marc

Who this course is for

Early-stage founders with an MVP that isn't gaining traction and a hunch they haven't validated the right problem yet.
Solo technical founders who build fast but avoid customer conversations because they don't have a repeatable process for them.
Repeat founders or corporate operators going independent who want a rigorous zero-to-one validation framework, not theory.

Prerequisites

You have an idea or early MVP to validate
This course is not for the pre-idea stage. You need a hypothesis, even a rough one, that you're trying to pressure-test with real humans.
You're willing to talk to strangers
Customer discovery means real conversations with real people. The cohort provides structure and accountability. The reps are yours to do.
No engineering background required for prototyping
The vibe coding tools in this course are designed for non-technical founders. If you can describe it, you can build it.

What's included

Live sessions

Learn directly from Marc Krejci in a real-time, interactive format.

4 Weekly Live Sessions

Four 90-minute sessions, one per week. Marc demonstrates live in the protovibing.ai canvas, the cohort works through the week's practice together, and every session ends with a public weekly commit the cohort tracks.

4 Weekly Project Deliverables

Each week you submit a real artifact: a customer hypothesis, interview synthesis, prototype share link, or Design Partnership Agreement. These aren't homework. They're the evidence base investors ask for at pre-seed and seed.

ProtoVibing Canvas + Async Feedback

Your individual project lives in the protovibing.ai canvas and includes a curated AI stack for capturing and synthesizing your customer work. Between sessions, Marc reviews your project and leaves feedback directly inside it.

Maven Guarantee

Your purchase is backed by the Maven Guarantee.

Course syllabus

4 live sessions • 4 lessons • 4 projects

Week 1

Jul 29—Aug 2

Jul

PMF Without Guessing | Week 1: Run Your First Full Loop

Wed 7/295:00 PM—6:30 PM (UTC)

Run Your First Full Loop

2 items

Week 2

Aug 3—Aug 9

Aug

PMF Without Guessing | Week 2: Build With Agents, Test With Humans

Wed 8/55:00 PM—6:30 PM (UTC)

Build With Agents, Test Against Both

2 items

Free resource

Presentation: How to Turn AI Prototypes into Validated Products

Most founders don’t fail because they can’t build. They fail because they build the wrong thing. In this 30-minute session, you’ll get a practical system for customer validation: how to run interviews that surface real signal, test prototypes with real users, and turn early adopters into design partners.

Schedule

Live sessions

1-2 hrs / week

One 90-minute live session per week, four weeks total. Live demonstration in the protovibing.ai canvas, group practice, volunteer hot seats, and a public weekly commit. Cohort is small by design so every student gets real feedback from Marc and peers.

Wed, Jul 29
5:00 PM—6:30 PM (UTC)
Wed, Aug 5
5:00 PM—6:30 PM (UTC)
Wed, Aug 12
5:00 PM—6:30 PM (UTC)
Wed, Aug 19
5:00 PM—6:30 PM (UTC)

Weekly Work

2-5 hrs / week

Each week you run 3 to 5 real customer conversations: discovery interviews early on, prototype tests as your build progresses. One project deliverable is due before each session. Marc reviews your work and leaves feedback directly in your project between sessions.

Testimonials

Marc’s program was truly transformative, with exceptional ROI. In a short time I gained more clarity, structure, and momentum than I’d built in months of working alone. His targeted guidance and proven frameworks saved me countless hours and gave me a confident, impactful path forward. I fully trust Marc’s experience and methodology, and I’m excited to continue working with him as I take my projects to the next level.
Rachel Guthrie
Principal CX Manager at Microsoft
Marc helped us focus on customer discovery and validation before building anything. We refined our ICP, mapped user journeys, and validated pain points early instead of jumping into code. The customer insights we gathered transformed how we understood our market. Marc brings experience from cutting-edge products used by millions, and it shows in how he helps teams validate the right problem before building solutions. This process delivered immediate clarity on product-market fit.
Greg Kostello
CTO at Cogzia
Marc's approach to customer discovery was eye-opening. He guided me through systematic validation of my business idea using customer interviews and user research methodologies I'd never applied before. Instead of building based on assumptions, I learned to validate pain points with real customers first. The customer insights I gathered gave me confidence that I was solving a real problem people would pay for.
Diana Schuetz
Founder at Safe Players
Before working with Marc, I had ideas but no systematic way to validate them with customers. Now I understand how to conduct proper customer discovery, validate pain points, and test assumptions before building features. The customer research framework he taught me transformed my approach from guessing to knowing what customers actually need. I strongly recommend this to anyone who wants to validate product-market fit.
Lubica Lutz
Lead Researcher at Pontis Foundation