After spending €50k on a product nobody paid for, I learned: validating a problem exists isn't enough. You need proof people will pay to solve it. Problem Ledger captures evidence while you browse. See someone complaining on Reddit? Save it. Read about a pain point? Capture it. Build proof a problem is real before investing time. - Browser extension (Chrome live, Firefox/Edge this week) - AI pattern detection - Watch Mode for passive capture One-time pricing, no subscriptions.