# Introduction

**three.dev** is a comprehensive AI observability and experimentation platform. Building and iterating with Large Language Models (LLMs) is incredibly powerful, but making changes often feels like a shot in the dark. A minor tweak to a prompt or an upgrade to a new model might perfectly optimize your application, or it could completely derail your user experience.

three.dev eliminates this guesswork. The platform empowers you to test the impact of any LLM-related configuration changes quickly, reliably, and rigorously, allowing you to move from intuition-based deployments to data-driven engineering.

#### Why three.dev?

To mitigate the risks of unverified LLM configuration changes, three.dev provides an advanced experimentation framework built around *your* specific definition of success.

With three.dev, you can:

* **Observe Your Baseline**: Get deep visibility into your current LLM usage so you understand exactly how your AI configuration is performing in production today.
* **Test with Statistical Rigor**: Confidently prove when one LLM variant outperforms another. three.dev's framework uses rigorous statistical analysis to ensure your results are reliable.
* **Evaluate Holistic Impact**: three.dev reveals the exact impact of your changes across multiple dimensions - including accuracy, cost, and latency - so you can make the best decision for your business.
* **Experiment with Total Flexibility**: Whether you are testing a brand-new foundation model, fine-tuning parameters, or just tweaking a system prompt, you can run experiments on absolutely any LLM configuration change you want to make.
* **Protect UX with Dynamic Routing**: Don't just run simple A/B tests. Evaluate multiple variants simultaneously (A/B/C/n) while the platform automatically minimizes traffic to underperforming configurations to protect your users.

Stop guessing how your AI behaves. With three.dev, you can observe, experiment, and ship with confidence.

Request access at [three.dev](https://three.dev).