Arize AI

Arize AI is an AI observability and evaluation company founded in 2020 by Jason Lopatecki, who is chief executive, and Aparna Dhinakaran, and based in Berkeley, California. Arize AX gives teams tracing, evaluation, experimentation and monitoring for machine learning models, LLM applications and AI agents in development and production. Its open-source project Phoenix provides tracing and evaluation for LLM applications, and the platform can also be self-hosted. Arize raised a $70 million Series C in February 2025.