I disagree that the type of coding the LLM is doing here is "expert" level in any meaningful sense. Look for example at the code for the bin-packing heuristics:

https://github.com/google-deepmind/funsearch/blob/main/bin_p...

These aren't complex or insightful programs - they're pretty short simple functions, of the sort you typically get from program evolution. The LLM's role here is just proposing edits, not leveraging specialized knowledge or even really exercising the limits of existing LLMs' coding capabilities.

To be clearer, the word “expert” in my comment above is in quotation marks because an LLM has more programming expertise than a non-programmer or an evolutionary algorithm, but not anywhere near a true expert programmer.