Topic
Networking & DNS
Records, TLS, routing and how to debug something that will not resolve.
explainer
DNS records explained without the hand-waving
A, AAAA, CNAME, MX, TXT, and the ones you only meet when something is broken. What each record actually does and when to use it.
in progress
A network troubleshooting checklist that fits on one page
From the physical layer upward, in the order that finds faults fastest.
in progress
TLS certificates and why renewal is always the outage
Certificate expiry is the most predictable outage in existence. Automate it, and monitor the thing that does the automating.