Wrapping up

Start to finish, by hand: a domain, a rented server, a hardened user, keys instead of passwords, a firewall, nginx in front of Node, a real TLS certificate, a WebSocket, a database, a fake deployment pipeline, and containers behind a load balancer.

Nothing in that list was magic. That was the point.

Three questions worth keeping

Why does CORS exist? You import a utility file from your own domain, fine. Import one from somewhere else and the browser blocks it by default — a cross-origin request. You don't control that origin, so a malicious actor could swap what it serves. CORS is you saying explicitly this origin, and nothing else. It's the same instinct as SSH keys and file permissions: the system making it hard to shoot yourself in the foot.

Is nvm fine on the server? Yes. The course installed Node globally because fewer moving parts means fewer things to go wrong on camera, not because nvm is wrong.

Can you build the image locally and pull it down? Yes — Docker Hub, the GitHub of images. Push yours, pull it anywhere.

Where to actually go

Every single topic here is a course, and several are careers. The honest map:

• The command line and Vim — you learned enough to survive; there are four hours of Vim alone.
• Linux — the OS section was one video deep.
• Databases — you wrote one CREATE TABLE. Joins alone are a subject.
• Containers and Kubernetes — orchestration was ten minutes of a two-day course.
• AWS — you used DigitalOcean specifically because AWS is a wall.
• Security — Jem spent more time here than anywhere and still called it not enough.

You are, as he puts it, now just enough to be dangerous. That's further than it sounds.