A recursively learning budget is shockingly hard to build

It’s non-trivial to build a recursively learning budget and forecasting system. Every change to a category, every correction, every edit to future spending should feed back into the learning engine so next month’s forecast is better than this month’s.

It sounds awesome. It is shockingly complicated to architect. Provenance for who changed what and why, guardrails that fail closed at the database, receipts for every migration, and a review surface that can handle a few hundred line items without a modal for each one.

I’m through the hard part, I think. Ask me again in October.