A postmortem of an IIoT ingress deployment failure: under Podman Rootless, EMQX 5.8 exposed unstable Erlang IPC, HOCON schema validation failures, a blocked security-group port, and M2M requests rejected by CSRF middleware. This post covers the confirmed causes, fixes, and validation path.
A postmortem on CPU optimization under a high-frequency polling workload: by shrinking the UI logging path, removing high-frequency state machines, and fixing the wait model, CPU usage dropped from 3.6%~4.2% to 0.1%~0.6%.
A postmortem on a failed recovery path under Rootless Podman + Systemd user units, covering confirmed contributing factors, concrete remediation work, validation steps, and remaining risks.
A security hardening postmortem for JWT AT/RT architecture: treating Redis reservation as completed and implementing RT rotation, replay detection, and revocable sessions.
A postmortem on a persistent 403 after HTTPS migration, traced to both missing CSRF allowlist updates and Podman Rootless image namespace isolation.