Human Signal

You can build almost anything now. The hard part is knowing what's worth building.

AI can turn an idea into a working product in a weekend. A convincing demo, landing page, or prototype is no longer evidence that you're onto something.

The evidence that matters is harder to manufacture: a real person choosing to pay, return, or refer.

Boris Manhart learned this the expensive way. He spent six years and more than 10,000 hours building a product downloaded by millions across Europe. The company was eventually sold. He walked away with nothing.

The underlying problem was painfully simple: we had built reach without true product-market fit.

Human Signal is the field guide he wishes he'd had then.

It's not another book about moving faster. In a world where building has become cheap, speed is no longer enough. The scarce advantage is knowing which signals deserve your confidence, which ones are noise, and what to test next.

The book gives you two practical instruments:

The Signal Stack helps you read the evidence in front of you. It separates what people say from what they actually do, so you can tell curiosity from intent and interest from genuine demand.

The PMF Flywheel helps you decide where to act next. Instead of endlessly building, pitching, and iterating, you focus on the question that matters now and use validated learning to move toward product-market fit.

You'll learn how to:

• Tell encouraging feedback from evidence of real demand
• Identify the signals that actually increase confidence
• Run a 72-hour test designed to produce learning, not activity
• Know what to test before investing months in building
• Recognize when you're selling your own story instead of listening to the market
• Decide when to persist, change direction, or stop

Human Signal is for founders and product leaders between an idea and Series A, technical founders who can build almost anything but need to decide what deserves to be built, and teams that can't afford to spend a year discovering they were solving the wrong problem.

If you've read The Lean Startup and wondered what changes when AI makes building dramatically faster and cheaper, this book starts there.

Praise for Human Signal

"The rare founder's book that teaches the real craft: hearing genuine demand through the noise before you lose years learning it the hard way."
- Stefan Telegdy, Serial Entrepreneur, CEO Mostly Mammals

"This book makes you nervous. With surgical precision, Boris takes apart the excuses founders use to gloss over their lack of product-market fit."
- Ollie Brunschwiler, Serial Entrepreneur, Co-CEO EBP Ventures

"Human Signal tells founders what to do on Monday morning. Practical, unsentimental, useful."
- Stefan Michel, Professor and Dean, IMD

The book also includes downloadable tools and additional resources to help you put the methods into practice:
human-signal.ai/downloads

Speed without signal isn't progress. It's just a faster way to waste the one thing AI can't give back: your time.

Read the signal. Build what your market is actually asking for.