World's Fair 2025
Evals 101 — Doug Guthrie, Braintrust
Overview
This talk introduces the concept and practical application of evals for AI systems, emphasizing their role in ensuring quality, reliability, and correctness. Evals provide a structured testing framework to move beyond the non-deterministic nature of LLMs, enabling developers to rigorously build and iterate on AI applications. The presentation highlights how evals facilitate a feedback loop between offline development and online production monitoring, ultimately leading to improved AI products.
Who should watch
- AI Engineers
- Product Managers
- Developers building AI applications
- Anyone seeking to improve the quality and reliability of LLM-based systems
- Those looking to establish a rigorous testing and iteration process for AI products
Key takeaways
- Evals are structured tests that measure AI system performance, focusing on quality, reliability, and correctness.
- The core components of an eval include a task (prompt or agentic workflow), a dataset (real-world examples), and scores (logic for evaluation).
- Evals can be performed offline (pre-production testing and iteration) and online (real-time monitoring of production applications).
- A key benefit of evals is the creation of a flywheel effect, connecting production logs and user feedback back into the development and testing cycle.
- The BrainTrust platform supports both UI-based and SDK-based eval creation and execution, allowing for flexibility in development workflows.
- Starting with a baseline eval and iterating is recommended over striving for a perfect dataset initially.
- Online scoring in production allows for continuous monitoring and early detection of regressions.
- Human-in-the-loop processes, combining automated review with human judgment, are crucial for refining AI applications.
Notable quotes
Evals are a really great way to play offense as opposed to just playing defense.
*Start and build that baseline. Establish that foundation that you can then improve upon.*
*The flywheel effect that this creates is one of the really fundamental value props of the platform.*
Unofficial community note. Prefer the recording for nuance.