Founder Topic

How do I know when I've found product-market fit?

The pattern across the archive: unsolicited demand is the only reliable signal. Shakeel Lala knew Marloo had it when advisors tried to buy a vibe-coded demo at a conference. Jevon Le Roux knew Keeyu's first version didn't when it turned out to be "a vitamin, not a painkiller." Validate demand before you build, ship before it feels ready, and treat growth metrics with suspicion until real money follows.

Product-market fit is the moment demand stops needing to be manufactured. Across the Founders In Motion archive, the founders who found it describe the same signal from different angles: people trying to buy before the product is finished. The founders who missed it describe the same trap — traction metrics that masked a product nobody truly needed.

Quick answers

What does product-market fit actually look like?

Unsolicited demand. Shakeel Lala's marker was advisors trying to buy Marloo's vibe-coded demo at a Brisbane conference — before the product existed. If you need a full pitch to explain the value, you're not there yet; his half-sentence pitch test is the bar.

How do I validate an idea before building it?

Research demand first. Caroline Tran's hard-won rule after building products "no one's buying": ask who the customers are, whether there's real demand, and whether they'll pay — before building anything. John from Affil.ai puts the YC version simply: "sell before you build."

Can traction hide a broken business?

Yes. Robert Huynh's team at Nook felt like they were "actually moving" because users and revenue grew — but burn rate, hidden costs, and shrinking margins meant the underlying business "didn't make sense." Growth metrics are not fit.

What separates a painkiller from a vitamin?

Whether it solves the crux of the problem. Keeyu's first version could detect e-commerce order issues but users still had to fix them manually — "it was a vitamin for retailers, it wasn't a painkiller." Will Bodewes shut down his first startup, a patented speaker company, for the same reason: he'd built "a nice to have."

What founders in the archive say

EP 27
Shakeel Lala · Marloo

$40M FinTech Founder on Raising Millions Before He Had a Business Idea

Shakeel quit his job, convinced one of Australia's largest VCs to back him with no business idea, ran 800 conversations with financial advisors over 9 months, then vibe-coded a demo the week before Australia's biggest financial advice conference. People tried to buy it on the spot. Marloo has since raised $10M and is live across 6 countries.

650+Financial advice firms now using Marloo across six countries, including the US, Canada, UK and Australia.
"You can vibe code your ideas. You can vibe code products. But you can't vibe code customers. And you can't vibe code sales. Distribution matters more than anything."— Shakeel Lala, on the limits of AI in early-stage building (15:30)
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EP 21
Jevon Le Roux · Keeyu

He Ran One of Australia's Biggest Athleisure Brands - Then Built Software to Fix Its Biggest Flaw

Jevon Le Roux ran retail brands like Surf Stitch and PE Nation before co-founding Keeyu — and he knew the product mattered when a customer, asked what she'd do without it, said "I just wouldn't come to work tomorrow."

1,000Customers during the Covid warehouse sale who paid but weren't going to get what they ordered
"there is that bit of angst that what they've ordered is not gonna arrive on time as promised — Jevon Le Roux, on the problem Keeyu solves (01:50) it turned out that that was a vitamin for retailers, it wasn't a painkiller — Jevon Le Roux, on the first version of Keeyu (11:08) we kinda don't have a product today, but would you be our first pilot customer — Jevon Le Roux, on landing the first pilots (10:31) you gotta get really comfortable with being rejected, you gotta get really comfortable being told it can't be done — Jevon Le Roux, on the most valuable lesson (21:50) she said I just wouldn't come to work tomorrow — Jevon Le Roux, recounting a customer's answer in a case study (25:50)"—
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EP 11
Vivek and John · Affil.ai (YC S24)

Inside Silicon Valley's $600B Startup School

Vivek and John got into YC with an idea the partners disliked, then landed their first paying customer with no real product — John manually skim-reading documents at "absolute blitz breakneck speed" while telling the customer the AI worked great. They sold before they built.

43Credit cards John has; he says he does this stuff for fun
"I mean the AI is just us, the AI is just me. They would give me thousands of euros and I would just like skim read them to like absolute blitz breakneck speed."— John, on how the first version of the product was just him (22:23)
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