I Built a $1M AI App [No Code] | Starter Story

David Rustler built a spreadsheet AI tool called Formula Bot that now has roughly 700,000 users, 5,000 paying subscribers, and about $26,000 in monthly recurring revenue. He built the initial version in a few weeks while his youngest child was on summer break, working a couple hours a day around a full-time job he kept for another year and a half. He had no coding experience. The entire first version was built on Bubble, a no-code platform he learned through YouTube tutorials. The story is less about a lucky break and more about what happens when a non-technical founder faces a series of existential threats — API bills that nearly sank him, copycat competitors, and eventually Microsoft and OpenAI building his product's core feature into their own tools — and adapts by changing what he builds rather than quitting.

The Viral Launch That Almost Killed the Business

Rustler's first customer was himself. He built an Excel formula generator because he was tired of junior colleagues knocking on his office door for help with spreadsheets. After a few weeks of work, he posted a link to the free tool on the Excel subreddit. It became the top post of the day, then the top post of the week. Someone suggested he cross-post to the "internet is beautiful" subreddit, where it got 10,000 upvotes and thousands of comments. Traffic poured in.