Human Signal — Finding Real Product-Market Fit in an AI-Built World

Written for the agentic era

When AI builds, signal becomes the moat.

The barrier to building has collapsed. The barrier to winning has not. When everyone can build anything, the winner isn't whoever ships the most code, it's whoever hears what real people do first, and tells a polite compliment from a genuine buying signal.

What you'll take away

From a vague idea to fit you can prove.

01

Read real demand

Tell polite praise from genuine pull. What people do, not what they say.

02

Experiments that answer fast

Tests that give you clarity in days, not quarters.

03

Know fit when it's real

Cohort retention, NRR above 100%, Sean-Ellis above 40%. Three strong at once is fit. One is a flattering metric.

04

Price on evidence

Anchor price to behaviour, the most honest signal your business produces.

05

Build defensibility

What do you have that a well-funded competitor starting fresh couldn't replicate within twelve months? Answer it, then build it.

06

Build in an agentic world

When AI ships the artifact in hours, you win on the signal it provokes. Turn any build into real evidence within 72 hours.

Who it's for

Built for the people doing the work.

Founders

Who have to find the one idea among ten that actually holds.

Product & growth teams

Who want to stop guessing and start gathering evidence.

SMBs going digital

Who want to grow without betting a fortune on a hunch.

The author

Boris Manhart

Operator & coach · Zürich

Boris is a Swiss entrepreneur and growth advisor who has spent over two decades building and scaling digital ventures. He led the consumer app CodeCheck, co-founded the unicorn Numbrs, advises startups through Growth Unltd. and Innosuisse, and is a startup strategist at IMD Business School. Human Signal distills what actually worked across those years, and, just as honestly, what didn't.

Substack · @borismanhart ↗

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