Evidence receipt / observation
Published · transcript-backedAishwarya Naresh Reganti: observation
11 Jan 2026 Lenny's Podcast Why most AI products fail: Lessons from 50+ AI deployments at OpenAI, Google, and Amazon
“I want to take two steps back and kind of talk about how much weight the term evals has had to take in the second half of 2025 because you go meet a data labeling company and they tell you our experts are writing evals and then you have all of these folks saying that PMs should be writing evals, they're the new PRDs.”
Source trail
Everything needed to verify it.
- Speaker
- Aishwarya Naresh Reganti
- Attribution
- Verified speaker
- Claim type
- observation
- Recorded
- 11 Jan 2026
- Publisher
- Lenny's Podcast
Transcript context
…Awesome. I want to take two steps back and kind of talk about how much weight the term evals has had to take in the second half of 2025 because you go meet a data labeling company and they tell you our experts are writing evals and then you have all of these folks saying that PMs should be writing evals, they're the new PRDs. And then you have folks saying that evals is pretty much everything, which is the feedback loop you're supposed to be building to improve your products. Now, step back as a beginner and kind of think what are evals? Why is everyone saying evals? And these are actually different parts of the process and nobody is wrong in the sense that yes, these are evals, but when a data labeling company is telling you that our experts are writing evals, they're actually referring to error analysis or experts just leading notes on what should be right. Lawyers and doctors write evals, that doesn't mean they're building LLM judges or they're building this entire feedback loop. And when you say that a PM should be writing evals, doesn't mean they have to write an LLM judge that's good enough for production. I think there are also very prescriptive ways of doing this and plus one to KD, which is you cannot predict upfront if you need to be building an LLM judge versus you need to be using implicit signals from production monitoring, et cetera. I think Martin Fowler at some point had this term called semantic diffusion back in the 2000s, which kind of means that someone comes up with a term, everybody starts butchering it with their own definitions and then you kind of lose the actual definition of it. That is what is happening to evals or agents or any word in AI as of today, everybody kind of sees a different side to it, I guess. But if you make a bunch of practitioners sit together and ask them, "Is it important to build an actionable feedback loop for AI products?" I think all of them will agree. Now, how you do that really depends on your application itself. When you go to complex use cases, it's incredibly hard to build LLM judges because you see a lot of emerging patterns. If you built a judge that would test for verbosity or something like that, it turns out that you're seeing newer patterns that your LLM judge is not able to catch, and then you just end up building too many evals. And at that point, it just makes sense to look at your user signals, fix them, check if you have regressed and move on instead of actually building these judges. So it all depends. I think one statement that every ML practitioner will tell you is it really depends on the context. Don't be obsessed with prescriptions they're going to change. That's such an important point, this idea that, especially that evals just means many things to different people now. It's just a term for so many things. And it's complicated to just talk about evals when you see it as the stuff data labeling companies are giving you and things PMR, right? And there's also benchmarks. People call benchmarks a little bit evals. It's like-…
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