Hardware PMF: How To Validate When Your Iteration Cycle Is 6 Months, Not 6 Days

Every lean startup principle was written for software. When your iteration cycle involves a manufacturing run, regulatory certification, or a supply chain negotiation, 'test and learn in two weeks' isn't a methodology — it's just an invitation to feel bad about constraints you can't change. Hardware PMF validation inverts the signal hierarchy. Customer commitment has to be weighted far more heavily than customer enthusiasm, because enthusiasm is cheap when the product doesn't physically exist. European hardware founders navigating CE marking, MDR, or RED directives face structural timeline constraints that no American framework accounts for. The question isn't 'do customers like what we're showing them?' It's 'will they commit in writing before the product exists?'