Why Building an Eval Platform Is Harder Than It Looks — Braintrust
Agent quality demands both pre-production evals and production observability to manage LLM non-determinism risks
“grading matters because LLMs are inherently non-deterministic”
Braintrust's Hussein frames agent quality around two pillars: offline evaluations before deployment and continuous observability in production, treating them as two sides of the same reliability problem. The core argument is that LLMs' non-determinism—their source of power—creates brand, compliance, and cost risks when agents become the primary way users interact with companies. Without systematic eval infrastructure, teams lack the confidence needed to ship reliable agents at scale.