Backups are only useful after a restore rehearsal
Choose a small recovery unit, verify it, and practice restoring it somewhere disposable.
Operations
DNS changes need a cache-aware rollback window
Prepare the TTL ahead of time, observe authoritative and recursive answers, and keep both endpoints valid through the cache window.
Redirects and error codes should preserve the story
Check the method, Location header, and cache behavior before choosing a redirect or an error status.
Reliable defaults beat clever recovery
Keep the common path explicit, observable, and safe to repeat before adding recovery branches.
Restart policies need a rate limit
Use an explicit service type, bounded restart behavior, and start-rate limits that leave evidence in the journal.
robots.txt and sitemaps answer different questions
robots.txt is a crawler-facing preference; a sitemap is a URL inventory; neither is an authorization layer.
SSH host keys are part of the deployment record
Record the expected fingerprint, use a deliberate StrictHostKeyChecking policy, and treat changes as an incident until explained.
The advantage of small systems
Small does not mean unfinished; it means each boundary has a clear job and a visible owner.