TensorZero is a Rust-based LLMOps platform that provides a unified API gateway for accessing multiple LLM providers with sub-millisecond latency. It includes built-in observability for storing and querying inferences, evaluation using heuristics and LLM judges, and experimentation features like A/B testing, routing, and retries. The platform integrates with the OpenAI SDK and OpenTelemetry standards, allowing incremental adoption alongside existing tooling.