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Why eval startups fail (2025)

thomasliao.com

51–60 of 66 posts

Re: Why eval startups fail (2025)

#51
I can see where Goodhart's Law applies to psychology and economics, pretty much any man-made domain without IDLH (immediate-danger-to-life-and-health) outcomes. But I think it's going to be hard to Goodhart a lot of medical AI safety. Biology doesn't give a shit.

However, identifying the right metrics and having the necessary test sets will, at times, be challenging.

Re: Why eval startups fail (2025)

#52
I have written a couple of eval harnesses to see how well LLMs drive software I have written. Basically I have data analysis software that I need LLMs to write code for. The code is complex, and I want to shape my APIs such that LLMs do a better job of quickly getting to the right answer. So I test different prompting and api surfaces, it's really easy to make quick gains this way and save your users from bugs. In this paradigm, I'm explicitly not testing different models, and I'm very interested to see how lesser models do with my software. Also for this type of testing, using the open weight models makes it faster, cheaper, and more reliable to test vs frontier models because I can trust that kimi-2.5-a-bunch-of-specs is going to behave more consistently than whatever tweaks Claude is making to Sonnet this week. API and prompting improvements seem to carry across the different models for gross improvements.

I haven't looked that hard, but I can't find articles about this type of eval testing, curious to hear if others have approached writing APIs in this way.

Re: Why eval startups fail (2025)

#54
post #46

"eval startups have a hard time finding customers, because clients have to be technical developers who want to build with APIs, but also not technical enough to run their own evals" To add to this, they have to be developers who aren't already using a fullstack observability solution, since it's fairly straight forward to add the eval startup featureset to an existing observability solution, and easier (plus cost eff…

Interesting. As someone who has written a fair amount of evals to test and benchmark my skills and tools, I am curious what observability solutions you might be referring to? /me heads off to ddg…

Re: Why eval startups fail (2025)

#55

Earlier quoted context omitted.

It's an important question! If you are paying a lot of money to use AI models, you care that you are using the best for your task. And it turns out that figuring out which AI models is best for your task is not trivial and requires some expertise.

That was too nice of a reply, I apologize. I just can't understand the thought process and that what exactly are we optimizing for? If you are paying a lot of money to use AI models, you already have so much overhead that precise ranking in an eval is not gonna make much difference between equally "frontier" models. Especially since models are sensitive to the input. So the eval is just gonna evaluate the eval with v…

There is a larger question of "do I need a frontier model for this" - knowing the cost/benefit tradeoff using frontier vs. e.g. local models is extremely valuable and takes skill to do!

Re: Why eval startups fail (2025)

#56

Earlier quoted context omitted.

(Author) It's short for "evaluation", a test for an AI model. Specifically, an AI evaluation comprises (1) a dataset of prompts (as questions / tasks / queries), (2) some way to score model performance on each prompt, like a set of correct answers or a grading rubric that you can use with an LLM autograder, and (3) a metric, such as accuracy¹. (If you're already familiar with the term "benchmark", it's the same thing…

That sounds a bit weak as a startup idea. Hard to productize, hard to scale, etc. It sounds more like consulting.

Yah - it's simultaneously the hardest and most vital part of machine learning work, and completely non-monetizable.

Re: Why eval startups fail (2025)

#59
It's also that the price-value frontier is different for different use-cases. For many of the things that I was doing, I could do harness improvements to make DS V4 Flash catch up in performance with GPT-5.5 or Claude Sonnet, but that's just because of the use-case. And if I'm being honest, this kind of eval doesn't need someone else. Claude and I can build a framework on a per-task thing.
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