The $40K/month website that does exactly one thing

Angus Chang built a website that converts PDF bank statements into Excel spreadsheets. That's it. The site does one thing, and today it generates $40,000 in monthly recurring revenue. Chang runs the entire operation alone—no employees, no co-founder, no outside funding. He bootstrapped it from zero and spent the first two years making almost nothing before the business took off.

How a personal frustration became a product

The idea came from a practical problem. After quitting his job in 2021, Chang wanted to understand his personal finances. He needed multiple years of bank data in a single spreadsheet to calculate his monthly spending. But his bank only provided PDF statements, and extracting transaction data from them was surprisingly difficult. He wrote code to solve the problem for himself, then realized others probably needed the same thing.

Rather than overthink it, Chang built a minimal viable product in about a week with a friend. They bought Google ads immediately to see if anyone would actually upload bank statements. People did. That was the validation. "If it takes you like one or two weeks to make an MVP, it's not that much of a risk anyway," Chang says. "So might as well just build it."