If you find this interesting, you might enjoy my write up of the Matoušek-Sharir-Welzl (MSW) algorithm used by D3’s circle-packing layout.

https://observablehq.com/@d3/d3-packenclose

I still haven’t quite figured out how to make D3’s implementation robust, though. Volodymyr Agafonkin’s robust-predicated would probably help… https://github.com/mourner/robust-predicates