This was around 2021 so AI code tools had not yet eaten everyone. One of the most interesting challenges was finding the right value judgements when blending multiple type systems. I doubt any agentic coding tool could do it today.

I blended the python type system with a large low-level type system (STEP AIM low level types) and a smaller set of higher-level types (STEP ARM, similar to a database view). I already was familiar with STEP, so I needed to really grok what Python was doing under the covers because I needed to virtualize the STEP ARM and AIM access while making it look like "normal" Python.

Oh, that's very interesting work. And, yes, I'd also be surprised if (today's) agentic tools were at all helpful for that: it's way outside of distribution, and conceptual correctness truly matters.