Daniel Katz is a Co-Founder of Rehearsals and a machine-learning builder whose background spans frontier AI, enterprise software, and company building. At Databricks’ Mosaic AI group, he worked on post-training for Databricks Assistant, the company’s AI coding agent. Before that, he built AI and engineering products at Microsoft across M365 Proactive Copilot and Microsoft Places.
Daniel had already built and exited a company before joining Rehearsals. As Founder and CTO of Brutus AI, he built model-creation and deployment infrastructure for clinical settings; the company was backed by Pear VC and acquired by Forta Health. His earlier work ranged from engineering at the Free Software Foundation to advocacy for vulnerable clients at the Alaska Public Defender Agency, giving him an unusually broad view of where useful systems meet real human needs.
