Lessons learned building a Kubernetes Auth Gateway

We're at the end of the series. Nine chapters of mechanism. One chapter of opinion. Building the Auth Gateway took roughly two years from "what if NGINX did the auth?" to "this thing handles every authenticated request in production." A lot of what's in the previous chapters wasn't obvious to us at the start. This is the post-mortem on our own architecture: what worked, what hurt, what we'd build earlier, and what we'd warn the next team about. What worked A few decisions held up cleanly. We'd m