Training Claude to get better at coding requires input from thousands of human software engineers. Bloomberg/Getty Images An Anthropic project is using feedback from about 1,000 human software engineers to improve the performance of Claude Code, the AI coding tool whose recent advancements have disrupted the vibe-coding industry . The project, known internally at Snorkel AI as "Marlin," focuses on fine-tuning Claude Code's answers so that it could mimic what a professional developer could do. AI companies like Anthropic often outsource data work to third parties like Snorkel , which hire contractors to teach AI a variety of specialist subjects and do other tasks to improve models. Contractor interviews and training material from these projects provide a look into how this unseen army operates across the world. Two contractors working on the Anthropic project told Business Insider they are being paid $280 per task to create prompts and review code.…