WordPress tells you the mail was sent. The customer never got it. This is a working guide to the four places WordPress email deliverability actually breaks: PHP mail() transport, SPF lookup limits, DKIM alignment, and DMARC policy. Includes real diagnostic commands, a troubleshooting order, and what changed now that DMARC has moved onto the IETF standards track.
Encrypting a Secret before you commit it only closes one of the five places that value comes to rest. Here is how to keep Kubernetes secrets out of Git properly: Sealed Secrets, SOPS and External Secrets compared honestly, the key-backup problem nobody plans for, and what to actually do when a credential is already in your history.
Every guide tells you to tick "Publicly Accessible" and move on. That works, and it also puts your warehouse on the internet with whatever credentials were to hand. Here's the full setup done deliberately: least-privilege user, narrow network access, and the outbound-only option nobody mentions.
You set PasswordAuthentication no, restarted SSH, and moved on. Months later the logs show successful password logins, because a vendor drop-in file sorted earlier and won. A VPS setup and hardening checklist where every step comes with the command that proves it worked.
Your browser shows a padlock and your partner's API client throws "unable to get local issuer certificate". Both are correct. A practical guide to the four things a TLS client actually checks, and to renewal automation that reaches the running server instead of just the disk.
A deploy key in GitHub secrets is a shell on your production server, handed to a container you don't control, running code from maintainers you've never met. Here's how to build the pipeline so a leaked key isn't worth much: forced commands, scoped sudo, pinned actions and a real approval gate.
Put a CDN in front of a dynamic site carelessly and it will cache one user's personalised page and serve it to everyone — invisibly, because your logged-in browser looks fine. Here is how to classify routes, set cache headers that hold, and run the two curl commands that catch the leak.
A fresh AWS account ships wide open by default. Here are the seven decisions that make one defensible from the start — OIDC instead of static keys, encrypted state, an isolated database tier, free gateway endpoints — with a working Terraform reference implementation on GitHub.
Almost every TLS certificate error traces back to one of three causes: a broken chain, a hostname the certificate does not cover, or an expiry nobody was watching. Here is how to tell them apart in under a minute, and how to stop the third one from ever happening again.
A working engineer's guide to HIPAA compliance on AWS, organised by the gap between the control you configured and the obligation you actually carry. Covers BAA account scope, the eligible services list as a contract boundary, KMS key policy versus the encryption checkbox, what "six years" really applies to, backup and restore scope, and the subprocessor chain nobody inventories.