THE PROBLEM
Vibe-coding tools optimize for output. They’ll happily generate a polished prototype for an idea no customer asked for. The compounding cost (wasted months, a sunk roadmap, no one who can explain why) comes due later, in the next funding round or the next planning review.
ProtoVibing flips the order. Sharpen the bet first. Talk to humans first. Write down what would falsify the idea, before you write the prompt that builds it.
“The validation loop runs on speed of feedback, not comprehensiveness of preparation.”
The Loop
01 · IDEA
Turn a fuzzy “what if” into a falsifiable hypothesis with a named customer and a specific problem. The Idea agent pushes back when reasoning is thin; it’s a thoughtful collaborator, not a cheerleader.
You leave with
a one-liner, a target customer profile, a hypothesis statement
02 · PLAN
Adaptive market and competitive research. Scope a P0 you can actually validate this loop.
You leave with
market context, P0 scope, visual direction
03 · CREATE
A disposable, frontend-only prototype scoped to the hypothesis. No premature backend, no scale plumbing.
You leave with
a working prototype that exists to be killed
04 · TEST
Set the go/no-go decision rule before running a single interview. Pressure-test your guide against synthetic personas. Run 8–12 customer-discovery sessions.
You leave with
a discovery guide, an experiment OKR, real transcripts
05 · SYNTHESIZE
Pattern-match real transcripts. Compare to the rule you wrote in Test. Decide: iterate, or commit.
You leave with
a synthesis doc, a graded hypothesis, a decision
BETWEEN LOOPS
Each loop dehydrates into a chip, learnings flow forward through bridge connectors, and Loop 2 starts pre-seeded with everything Loop 1 discovered.
THE DECISION
Iterate (with a refined hypothesis), or commit (with the artifacts to ship). No rationalizing the result post-hoc; the decision rule was set before you ran the test.
THE OUTCOME
By the time a ProtoVibing loop closes, you have artifacts that won’t move under you: a one-liner that survived customer pressure, an ICP grounded in real interviews, a hypothesis with explicit test sentence, transcripts and patterns from the field, a written go/no-go that was set before testing began. That’s the position to build from. That’s what makes the next six months feel like execution instead of guesswork.
ONE-LINER
Survived customer pressure
ICP DOC
Grounded in real interviews
HYPOTHESIS
With explicit test sentence
TRANSCRIPTS
Patterns from the field
DECISION
Set before testing began
THE HANDOFF
Close a loop and ProtoVibing syncs every confirmed document into a GitHub repo you own. It arrives as an AGENTS.md and CLAUDE.md your coding agent reads before it writes a line, next to the full dossier and one folder per loop. The industry has started calling this a project constitution. Without one, a build drifts back to the assumptions your loops were built to kill.
See how the handoff worksNOT ALONE
Invite co-founders, advisors, stakeholders, and design partners directly onto the canvas. They comment on specific nodes, not generic threads, so feedback lands in context. Advisors and sponsors can sign-off (or block) phase advancement. They catch up on a project in 10 minutes from a link, not a Zoom briefing.
“I spent three months validating in Claude and had nothing to show my co-founder except a folder of chat logs. ProtoVibing changed that. I shared a link and she was caught up in 10 minutes.”
WHO’S RUN IT
“ProtoVibing 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. The targeted guidance and proven frameworks saved me countless hours and gave me a confident, impactful path forward.”
“ProtoVibing 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. This process delivered immediate clarity on product-market fit.”
“The ProtoVibing approach to customer discovery was eye-opening. It 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.”
“Before discovering ProtoVibing, 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. I strongly recommend this to anyone who wants to validate product-market fit.”
WHAT IT LOOKS LIKE
Demo state · loop1-decision
When a loop completes, the decision point appears in your workspace. Iterate or commit, with your full validation history one click away.
Demo state · loop2-in-progress
Loop 2 starts where Loop 1 left off. Insights flow forward through bridge connectors, not buried in chat logs.
Demo state · three-loops-done
Every loop, every artifact, every advisor comment. One workspace, scroll back to the moment a hypothesis got disproven.
FREE STANDALONE AGENTS
These free standalone agents run inside Claude or ChatGPT. They don’t coordinate the way the platform does, but they’ll move you forward today.
sharpen the pitch
Pressure-tests your one-liner and rewrites it with three customer-specific variants. Each variant names a different segment and comes with the exact evidence that would falsify it.
lock the hypothesis
Generate a testable one-sentence bet: named customer, specific problem, and the claim about why they'd choose you. Falsifiable from the first draft.
define the customer
Walk from a broad demographic to a specific, named customer segment. Returns a profile covering what they're trying to accomplish, the workaround they're stuck with today, and what would make them switch. Ready to guide your first customer interviews.
These give you a taste. The platform wires them all together, and adds your team and your customers.
ACCESS
ProtoVibing runs on two components: per-seat access to the platform and agent suite, and usage credits for AI-assisted loop work. Exact pricing is shared during onboarding. We're calibrating the model with our early design partners.
Practitioner
Solo founders and individual PMs, early exploration
Access the methodology, practice the prompts in plain Claude or ChatGPT, and get notified when early access opens.
Design Partner
Early design partners
A curated group of founders and product teams running real validation loops inside the platform, guided by the full agent suite, with advisor oversight baked in.
Team
Founding teams and product teams
Shared workspace for co-founders, PMs, designers, and engineers running loops together, with team-level advisor and stakeholder visibility.
Pricing details are shared during onboarding. We're building the right model with our first design partners.
SERVICES
The platform is the self-serve path. These are the hands-on options.
CONSULTING
A 1:1 consulting engagement with Marc. Over five days, one session per phase, he walks you through a complete ProtoVibing loop (Idea through Synthesize) as a hands-on collaborator, not a coach watching from the sideline. You leave with a fully executed loop, a written iterate-or-commit decision, and a grounded working knowledge of the methodology you can apply independently on every loop that follows.
WORKSHOPS
ProtoVibing consulting workshops run as public events, structured cohorts, and private sessions for accelerators, founding teams, and product orgs. All formats are hands-on: you leave with a sharpened hypothesis and the muscle memory to run the next loop yourself.
WHO BUILT THIS
Marc Krejci has spent over twenty years shipping software products, including 7.5 years leading design for AI, VR, and ML-driven experiences at Meta. He developed the ProtoVibing methodology through direct work with more than 200 early-stage founders, building a system to interrupt the failure patterns he kept seeing repeat.
200+
Founders coached
20+
Years shipping
8
Ventures founded
APPLY
Drop your email and stage and you’re on the list. Continue into the validation-readiness diagnostic for a scored result, a recommended starting phase, and consideration for design-partner access.
APPLY
Drop your email to hold your spot. Take the seven-question diagnostic for a scored readiness report, a recommended starting phase, and consideration for a direct working session with the team.
FAQ
Design Partners get hands-on access during the beta: direct 1:1 time with the Pathfinder Foundry team, early platform access, and influence over the methodology. Waitlist signups stay in the loop for the eventual public launch. It’s the same form: drop your email and your stage and stop, or continue into the seven-question diagnostic to be considered for the current design-partner beta.
Those tools optimize for output. ProtoVibing optimizes for the validity of the bet you’re betting on. We force a falsifiable hypothesis, a named customer, and a written go/no-go decision rule before the first prompt. The prototype gets built only to test something specific, never as the goal itself.
No. The Create phase produces a frontend-only prototype using AI tools you already use; people who can already code move faster, but the methodology doesn’t require coding skill. Validation rigor is what compounds, not raw build velocity.
It works in both, and the loop is identical. What changes is who witnesses it. A founder brings co-founders and advisors; a product team brings its design partner, its engineering lead, and whoever signs off on the roadmap. The decision rule does the same job in either place: it gets written before the interviews so the result can’t be re-argued afterward. Teams inside companies usually have easier access to customers and a harder time getting permission to kill an idea. The written go/no-go is what makes that second conversation short.
An idea you can articulate in a sentence and a few hours a week to commit. That’s the floor. If you don’t have an idea yet, the Idea phase is built to help you sharpen one, but we’re not in the business of generating ideas for people who don’t have them.
A loop moves as fast as you have time to move through it. With AI-assisted tools accelerating every phase except one, a committed team can compress Idea through Create into days. The bottleneck is almost always the Test phase: scheduling and completing real customer interviews takes as long as it takes. That is not a flaw in the methodology. It is the point. The fastest possible loop is one where the interviews are done, not skipped.
A GitHub repo you own. Every document you confirmed during the loop is synced there: the combined dossier at the root, the product, spec, market, and build sections as individual files, and one folder per loop holding that loop's synthesis. Each closed loop arrives as its own pull request, so your validation history reads back as commit history. Today the repo carries validation documents rather than runnable code, which is the point. It is the foundation the real build answers to.
Yes, and this is the part most people don't expect. Agentic build tools look for a root AGENTS.md or CLAUDE.md to ground themselves before they start writing. ProtoVibing writes both, containing what the industry is starting to call a project constitution: the decisions and requirements that were actually tested with customers. Point Claude Code at the repo and it reads your validated learning first, then builds against it, instead of reintroducing the assumptions your loops were designed to kill.
Your project, transcripts, and artifacts stay private to you and the people you explicitly invite. We don’t train models on your work. Service-role access is reserved for product operations only.
After our early design partners close a full validation loop and we’re confident the experience holds up. Everyone on the list gets notified, in order of join date.
