Without tests, every change is a bet.
A new prompt, another tool, a better answer: any adjustment can fix one thing and break three that were already working. And it doesn’t matter who makes it: even if the best prompt engineer in the world writes the change, without a way to test it nobody can guarantee it works, or that it didn’t damage what came before.
Certainty doesn’t come from who makes the change. It comes from being able to test it.
That’s what Evals are for.
The unit of improvement isn’t the prompt. It’s the eval.
An eval is your agent’s quality contract: it defines what has to be true in a given situation, no matter how the agent gets there. The prompt describes how to speak; the eval defines what “correct” means.
- It defines success. Every requirement becomes a measurable criterion, agreed with you from day one.
- It protects what already works. On any change, we run the suite and know instantly whether it broke something that worked before.
- It grows with your operation. Every lesson learned adds an eval. Your quality library improves on its own over time.
See it in the product
A walkthrough of how a change gets tested before a customer ever sees it:
Predict before production. Confirm on what’s real.
Evals run in two places, and they answer two different questions.
Before production, synthetic users. We simulate dozens of conversations against your agent with realistic profiles: the decisive one, the confused one, the annoyed one, the one who tests the limits. You see whether a change works in minutes, before a real customer lives through it.
In production, real conversations. Every night we run the same evals over a sample of real conversations and measure whether your agent still holds up. The safety net that never sleeps.
One anticipates impact. The other confirms it on the ground.
Evals don’t replace your business metric. They isolate it.
Your business is the real yardstick of impact: if the agent sells, it sells. But that metric moves for many reasons at once, and you can almost never tell how much of it was the agent.
- Better ads bring in better users and sales go up. The agent didn’t change.
- Inventory drops, only the weak products are left, and sales go down. The agent didn’t change.
An eval answers a single question, clean of the business noise: is the agent doing well what we set it up to do?
When you improve the prompt and eval coverage goes up with the business untouched, that’s an early indicator you’re going to close the month better. And it arrives sooner: an eval gives you signal in hours; a business metric takes weeks to become significant.
Reliability that scales
Every change validated in minutes, with evidence instead of faith. Your agent improves fast without losing what already worked, and that quality holds even as conversations grow.
- Minutes to know whether a change works, instead of waiting for real traffic.
- Zero surprises: regressions caught before a customer lives through them.
- Certainty: evidence on every change, not a bet.
Want to see it on your own agent? Book a demo.