besides "show hn", and "ask hn", there should be a 3rd category: "inspire hn" where we open-source and workshop brilliant ideas that are just waiting for some genius to come along and implement them. @dang ? :)

a spreadsheet ui for a higher-order jupyter notebook where each cell is a jupyter notebook or cell, and calculations flow into and out of cells like Monads or Arrows, would be genius !

Observablehq notebooks are reactive but JS only. Jupyter is becoming a standard but the lack of a DAG for reactivity and the difficulty in version controlling them are serious limitations.

Julia ecosystem has an awesome tool called Pluto that solves this. https://github.com/fonsp/Pluto.jl it is still young but actively developed. I am especially looking forward to their upcoming 2D Grid layout option, which will essentially turn it into a code driven reactive dashboard.