IPinfo

A developer turned a simple side project—an API that returns accurate geolocation data for any IP address—into a subscription business generating over $500k per month. The service grew by solving a universal developer need with a clean, reliable interface, handling billions of API requests for thousands of companies that rely on it for analytics, fraud detection, and content localization. By focusing relentlessly on data accuracy and developer experience rather than flashy features, the founder proved that well-executed infrastructure tools serving everyday technical needs can scale into highly profitable businesses.