Customers, like founders, have a gap between their stated beliefs and actual behaviors. Instead of relying on discovery interviews, watch them work. Observing their actions reveals their true operating philosophy—what they genuinely value—which is a more reliable guide for product development than what they say.

Your first customers require obsessive, daily interaction to ensure the product works for them. Astronomer's founder spoke with their first managed Airflow customer four times a day for two months. This grueling process is essential for ironing out roadblocks and achieving product-market fit.

Rushing to market without validation is a recipe for failure. Instead, engage potential buyers and proposition leads as 'critical friends' in focus groups. Use their feedback to build a white paper, refine messaging, and create a product they actually need, even if it takes a year.

Initially, customers often "round down," focusing on missing features. A key sign of product-market fit is when they start "rounding up"—their faces light up in demos, and they imagine the product's future potential, forgiving current limitations because they believe in the core value.

Founders often create complex plans and documents to avoid the simple, hard, and uncomfortable task of selling. Just as getting stronger requires consistently lifting heavier weights, finding product-market fit requires consistently doing the core work of talking to customers and trying to sell.

The ultimate signal of product-market fit is when your go-to-market strategy simplifies to 'get a customer in a room with a prospect.' When customers become your most effective sales channel, you have found it, and your team can 'walk away'.

Technical founders often create a perfect solution to a real problem but still fail. That's because problem-solution fit is useless without product-market fit. An elegant solution that isn't plugged into the market—with the right GTM, pricing, and messaging—solves nothing in practice. It's unheard and unseen.

For products targeting specialized professionals like pilots, credibility is paramount. The most effective way to ensure product-market fit and user adoption is to hire an actual end-user (like a pilot) onto the product team. They can co-create concepts, validate language, and champion the product to their peers.

Product-market fit is confirmed through repetition. For Decagon, it was when the fifth and sixth customers independently described the same core problem, cited the same failed competitors, and expressed immediate willingness to buy, proving a repeatable market need.