I wonder if this makes AI models particularly well-suited to ML tasks, or at least ML implementation tasks, where you are given a target architecture and dataset and have to implement and train the given architecture on the given dataset. There are strong signals to the model, such as loss, which are essentially a slightly less restricted version of "tests".
I'm certain this is the case. Iterating on ML models can actually be pretty tedious - lots of different parameters to try out, then you have to wait a bunch, then exercise the models, then change parameters and try again.
Coding agents are fantastic at these kinds of loops.
We've been doing this at work a bunch with great success. The most impressive moment to me was when the model we were training did a type of overfitting, and rather than just claiming victory (as it all too often) this time Claude went and just added a bunch more robust, human-grade examples to our training data and hold out set, and kept iterating until the model effectively learned the actual crux of what we were trying to teach it.