Not Diamond is a San Francisco-based startup building a data-driven recommendation layer for AI, positioning itself as a routing algorithm that analyzes queries and sends each one to the best-performing model rather than relying on a single monolithic LLM. Beyond intelligent routing, it offers Prompt Adaptation, an agentic black-box prompt-optimization system that automatically rewrites prompts across models, which the company says replaces 25+ hours of manual prompt engineering with roughly 30 minutes of processing. It was founded by Tomás Hernando Kofman, Tze-Yang Tung and Jeffrey Akiki.
Funding
Not Diamond raised $2.3 million in pre-seed funding announced in July 2024, led by defy.vc. In 2025 it took additional strategic funding from defy.vc, IBM, SAP.iO Fund, Myriad Venture Partners, Deepwater Asset Management, DNX Ventures and Ambush Capital (amount undisclosed).