Docker

The 4% rule is a single number from a black box. Here's what happened when we applied normal infrastructure-engineering instincts — validate against known benchmarks, make the methodology inspectable, self-host the thing — to the math behind safe withdrawal rates, and the open-source tool that came out of it.

How we built a production mail server from scratch — Postfix, Dovecot, dual DKIM, DANE, DNSSEC, MTA-STS, WKD, and an SNI multiplexer — with Part 2 covering post-quantum OpenPGP on the horizon.