Arthur is a New York-based AI governance and observability company that gives enterprises a single control plane to discover, monitor, evaluate, and govern the AI models and autonomous agents running across their organization. Founded in 2018 by a team out of Capital One and academia, Arthur started with machine-learning monitoring - catching model drift, bias, and performance decay in production - and has since expanded into real-time guardrails, LLM evaluation, and agentic AI governance. Its open-source Arthur Engine and its Agent Discovery & Governance platform help security, compliance, and ML teams ship AI they can trust in regulated industries like finance, insurance, healthcare, and government.
Openlayer is an AI governance and observability platform that helps enterprise teams test, monitor, and trust their machine learning and LLM systems across the full lifecycle - from prototype to production. Founded by ex-Apple, Amazon and Harvard alumni and backed by Y Combinator and Race Capital, the company raised a $14.5M Series A in May 2025.
Arize AI builds the observability layer for AI - a platform engineers use to trace, evaluate, and debug models, agents, and LLMs running in production. Its open-source Phoenix library and enterprise platform are used by companies like Uber, DoorDash, Instacart, Reddit, Booking.com, and Duolingo to make AI systems work in the real world.
Fiddler AI is a Palo Alto-based enterprise AI platform that operates as a control plane for compound AI systems and autonomous agents, providing real-time observability, security, governance, and guardrails for ML models and LLMs in production.