The bug that killed every signup for 4 days My signup flow asked users to pick a paid plan before they had ever seen the product. Conversion was rounding to zero. Vantage launched on April 22. By April 28 I had four signups. Four. The site was getting traffic — Vercel Analytics confirmed it — but almost nobody was making it from the landing page to a working account. I assumed it was the price. I assumed it was the copy. I assumed it was the demo. I rewrote the hero three times that week. It was none of those. It was a step in the signup flow I had completely forgotten was there. The "plan picker." Before a user could create an account, my code routed them to a screen that said "pick your plan" and showed three options: Free, Pro (£12/month), Enterprise. They had not seen the product yet. They had not run a single analysis. They had no information.…