Notes on building systems.Notes on building systems.

8 Sept 2026·9 min·hushgate

Ninety-one ways to check one number

A German account number carries a check digit, but which arithmetic produced it is a property of the bank, not the number. Closing that gap in hushgate meant shipping the Bundesbank’s directory — and turning the library I chose not to depend on into the thing that tests me.

23 Aug 2026·8 min·hushgate

The PDF was going through untouched

hushgate redacts prose, and people attach documents. Closing that gap meant deciding not to parse PDFs myself — and learning that the dangerous failure is not an error, it is a success with nothing in it.

03
Running large models on hardware I own
self-hosted AI
draft
04
Cloud vs. on-prem: where GDPR draws the line
hybrid architecture
draft
05
NAT, port-forwarding, and the joy of self-hosting
networking
draft