Courtney Fahnhorst, a wound care and hyperbaric medicine specialist, was looking for a way to supplement her income when she found a LinkedIn ad seeking medical experts to help train AI models. She has been working with the AI software for two years, sharing her 15 years of medical experience and evaluating the model's responses to clinical situations. Fahnhorst was initially drawn to the opportunity for its flexibility, but she has also found it has rekindled her passion for medicine. The salary is competitive, and she appreciates the ability to work on her own schedule. Fahnhorst is one of 30,000 experts working with Mercor, a company that pays an average of $80 per hour and about $3 million per day in total. Mercor is just one of many companies that exchange career knowledge for cash, and it works with a range of clients, including frontier AI companies and Fortune 500 enterprises. The company's head of communications, Heidi Hagberg, says that the experts work with Mercor to earn a flexible side income, gain AI skills, and have a direct hand in improving the software's outputs. The task of manually teaching technology is not new, but the size, scale, and speed of the industry have exploded in recent years alongside the growth of AI platforms. As AI agents seek to complete multistep processes, they require more advanced domain expertise, and companies like Handshake are evolving to meet this need. The industry is expected to continue growing, with insiders predicting it will double in the next year and again the year after that, creating a boom in AI-related jobs.