Fortune reports that AI unicorn Mercor has acquired Deeptune, an Andreessen Horowitz-backed startup that builds simulated environments where AI agents practice tasks in tools like Excel, Salesforce, and Slack before being trusted with the real thing. Terms weren't disclosed. Mercor runs a network of domain experts who design the tasks and scoring rubrics used to train frontier models for clients including OpenAI and Anthropic; Deeptune supplies the digital replicas those tasks run inside. Fortune noted Mercor founder Brendan Foody had personally invested in Deeptune's funding round just months before buying the company outright. Deeptune's team is relocating to New York as part of the deal.