Justin Smestad

After maintaining an authentication library with 125 million downloads for over a decade, here’s what I learned about the real cost of auth: it’s not the build, it’s the maintenance nobody plans for. And no, an AI agent monitoring your dependencies isn’t the answer.

AI made code cheap. The bottleneck was never the code. It was scoping, estimation, and communication, the skills teams treated as optional for years. That bet no longer pays off.

Constants feel clean until six files break when you rename a hash key. Class methods give you the same performance with an API boundary that survives refactoring.

Deep linking looks simple until it breaks in production because three teams own different pieces of it. Here’s the Phoenix server-side setup, including the content-type gotcha that will cost you an afternoon.

A Makefile trick that auto-populates the ngrok hostname into your Phoenix dev server. Small dev-environment friction compounds across a team faster than you’d expect.