How they earn: He solo-developed "TypingMind," an interface that makes AI models like ChatGPT and Claude more comfortable to use. On a self-reported basis, it has reached roughly $130K–160K per month in revenue.
How they do it: He built out a power-user UI that lets you use multiple providers' APIs in one place, and attracts users by sharing his development process and numbers on X (formerly Twitter) — the "build in public" style.
What you can learn: Powerful AI is often "hard to use as-is," and even just the "usability layer" that makes it comfortable can become a business. A great example of creating value without building the underlying model yourself.