I'd helped build enterprise pipelines at work, but so much of the machinery stayed hidden behind shared libraries and platform teams that I never fully grasped the fundamentals. So I rebuilt the whole thing by hand with the modern open-source stack — GitHub Actions, Docker, GHCR, k3s, Helm, Trivy, and ArgoCD. The demo is interactive: a message you type becomes a real commit, which kicks off CI (test → build → scan → push) and then a GitOps continuous-delivery loop where ArgoCD reconciles the cluster to match Git. The twist is that deploying rebuilds the very backend you're talking to mid-conversation, which forced a stateless progress tracker that survives the server replacing itself. The whole point was to be able to say I understand every step from 'git push' to 'it's live' — and now I can.