Claude Code for Canary Deployments: How I Ship to 1% of Users Before Breaking Everything

I used to ship by faith. The change passed code review, the tests went green, the deploy button was right there, and I pressed it. Most of the time it was fine. The handful of times it was not fine cost me weekends, customer trust, and a real amount of money. The worst incident I can remember was a single line change that took down checkout for forty minutes during a marketing push. The change had passed every test we had. The bug only showed up under real traffic patterns. After that incident,...