https://github.com/GoogleChromeLabs/critters Might be a good starting point. It’s designed to inline the css afterward so it’s more focused on extracting used css than removing unused.
Slurm [1] is a open-source HPC scheduler thats a good example. Its featureful and (surprisingly) easy to run if no user accounting (i.e., accounting for individual computation budgets) is needed.
The Evolutionary Computation Bestiary [1] list a wide variety of animal behavior inspired heuristics.
The foreword includes this great disclaimer:
"While we personally believe that the literature could do with more mathematics and less marsupials, and that we, as a community, should grow past this metaphor-rich phase in our field’s history (a bit like chemistry outgrew alchemy), please note that this list makes no claims about the scientific quality of the papers listed."
This is a good example for an interactive non-SPA. JS only for cosmetics and all state is fully stored in the URLs. The main pages could even be statically generated (858705 combinations * 3 views * 8KB = 20GB).