Guides · Utiltown
Guides
Reference sheets, comparisons, and troubleshooting walkthroughs written around real engineering problems — the kind of reading that pairs with our browser tools.
Cron Syntax Cheat Sheet: 6 Schedulers Side by Side
The same cron expression can mean different things in crontab, systemd timers, GitHub Actions, Kubernetes, Quartz, and Windows Task Scheduler. Field layouts, day-of-week numbering, and @shortcuts compared in one reference table.
TroubleshootingCron Job Not Running? 9 Causes and a Systematic Fix Path
A systematic checklist for cron jobs that never fire or fire at the wrong time: schedule mistakes, timezone traps, environment differences, logging, and platform gotchas — with concrete commands for each step.
ComparisonYAML vs JSON: Which Format for Configuration, APIs, and CI
Where each format wins: comments, anchors, type coercion surprises (the Norway problem), multiline strings, and ecosystem fit. A decision table for CI, Kubernetes, OpenAPI, and app config, plus a safe round-trip conversion workflow.
ExplainerJWT: Decoding vs Verifying — What Is Safe to Trust in the Browser
Why "decoding" a JWT is not "validating" it: the three parts of a token, what signature verification actually proves, where decoding in the browser is safe, and where it must never be trusted.
ReferenceBase64 and Data URI Cheat Sheet: Prefixes, MIME Types, and Common Pitfalls
The data URI format at a glance, the MIME types you actually use, padding and URL-safe variants, the Unicode pitfall in JavaScript, size overhead, and when data URIs are the right choice — with copy-paste examples.