Product Discovery: Validating Before You Build

Clickable prototypes tested on real tasks, concierge/wizard-of-oz versions of the service, landing-page demand tests — evidence per dollar, weeks before code.

Before discovery starts: what evidence proceeds, what evidence kills — decided in advance because sunk-cost reasoning is undefeated otherwise.

Skipping the discipline this article describes until an incident, audit, or stalled project forces it — every practice above is cheaper adopted early than retrofitted under pressure.