Arize

Arize AI provides an AI engineering platform for observing, evaluating and improving AI agents and applications. Its commercial product, Arize AX, captures traces of agent runs (inputs, outputs, tool calls, latency, token usage and cost), surfaces recurring failures as ranked issues through a feature called Signal, scores quality using LLM-as-a-judge, agent-as-a-judge and code evaluators, and validates changes through datasets and experiments before deployment. The platform includes Alyx, an in-product AI engineering agent that runs evaluations, debugs issues and proposes fixes, and ADB, a datastore for GenAI traces that stores data in open formats for connection to BigQuery, Databricks or Snowflake. Coverage spans generative AI, AI agents, traditional machine learning and computer vision, including chatbots, RAG systems and copilots.

Alongside the commercial product, Arize maintains Phoenix, an open-source, local-first platform for tracing, evaluation, experimentation and prompt iteration, launched in 2023. The company also originated OpenInference, a set of GenAI semantic conventions built on OpenTelemetry. Arize AI Copilot, described as an AI assistant for AI engineers with over 50 built-in skills, launched in 2024. The company states its platform integrates with 40 or more models, frameworks and AI tools, including OpenAI, Anthropic, Google, Amazon Bedrock, LangGraph, LangChain, LlamaIndex, CrewAI, the OpenAI Agents SDK and DSPy, and runs across Google Cloud, AWS, Azure and self-hosted environments.

Founding story

Arize was founded in 2020 by Jason Lopatecki and Aparna Dhinakaran, who shared a frustration that machine learning investments were growing rapidly while teams lacked the tools to understand why models behaved as they did once deployed. The founders' initial seed deck opened with the line "We Make AI Work," and the company set out to give teams the means to troubleshoot and improve AI performance in production.

Business model

Arize sells a managed SaaS and self-hosted platform (Arize AX) on a tiered subscription basis while distributing an open-source tool (Phoenix) that developers can host locally, with an upgrade path to the commercial product. A dedicated startup pricing program is offered.

Tiered subscriptions: AX Free at $0 per month (25k spans, 1 GB ingestion, 15-day retention, 10 Signal issues per month, SaaS only), AX Pro at $50 per month (50k spans, 10 GB ingestion, 30-day retention, 25 Signal issues per month), and AX Enterprise with custom pricing, custom volumes and retention, unlimited Signal issues, SaaS or self-hosted deployment, enterprise SSO, audit logs and SLAs. Users and evaluations are unlimited on all tiers.

Traction

The company's site reports 1 trillion spans processed, 1 billion evaluations per year and 5 million downloads per month; the February 2025 blog post cited over two million monthly downloads for Phoenix. The about page lists a large employee roster and 28 open positions.

Latest developments

In February 2025 Arize announced a $70 million Series C led by Adams Street Partners and an expanded Microsoft partnership covering Azure AI Studio and Azure AI Foundry integrations. Its current product line centers on Arize AX with Signal, the Alyx AI engineering agent, the ADB trace datastore and agent-native debugging workflows for coding agents. The homepage announces "A new chapter begins with Dynatrace."