A small engineering journal

Notes about networks, tooling, and the things I keep forgetting between projects.

• Measuring latency without lying to yourself What ping leaves out, and why your numbers disagree with the dashboard.
• A checklist that keeps a mail server alive The unglamorous parts: queues, backups, and the certificate nobody watched.
• “Slow internet” is usually DNS Three outages in one month, one resolver, and a lesson about TTLs.