Uri Merhav spent years as a machine learning engineer at LinkedIn before leaving the salaried corporate life to cofound DocuPanda, a service that reads messy documents and returns clean structured data. In a November 2024 post on his own Substack, he argued that aspiring founders waste too much time on market sizing and analysis paralysis. His counterpoint was practical: pick an itch, build a thin version of the fix, and try to get a stranger to pay for it within a day.

He picked an itch he kept running into while selling DocuPanda. Healthcare and financial customers wanted to test the product but first had to scrub personal details out of their sample documents, which was tedious. So he built pdf-redact.com, a tool that finds personally identifiable information in a PDF and draws black boxes over it automatically. When he found three competitors already buying Google Ads for "PDF redaction," he read that as proof the niche pays, not as a reason to quit.

The build was deliberately quick. He cloned the existing DocuPanda codebase as a starting template, gutted almost all of it, and rewrote the onboarding flow to redact PDFs instead. The frontend (drag-and-drop redaction boxes over an uploaded document) came together by prompting GPT repeatedly rather than from deep frontend expertise. The backend reused DocuPanda's own API to locate sensitive sections and return their coordinates. His stack was Vercel, React, Material UI, Firebase auth, and Stripe for billing. Naming, logo, and branding took minutes.

Once it was live, he pointed a roughly thirty-dollar-a-day Google Ads campaign at keywords like "redact PDF" and "remove PII from PDF" to get a first signal. Within a day the tool had taken its first nineteen dollars. Merhav was upfront that this was a tiny number and not a money hack, just early evidence that someone on the internet will pay for a basic but genuinely useful thing.

The honest framing matters here: pdf-redact.com was a fast experiment to make a point, and the page no longer resolves. DocuPanda, the flagship he cofounded in 2023, is the long-running business that powered it and has since been rebranded as DocuPipe.ai. The lasting takeaway from his write-up is the method, not this particular tool: ship something small that works, charge for it, and learn from a real payment instead of a spreadsheet.