Developer guides

Background notes that a tool interface alone cannot explain. Each guide covers the concept and the problems that come up in practice, and links directly to the tools involved.

All guides (8)

encoding When and why to use Base64 encoding What problem Base64 was designed to solve, where you meet it in practice, and why it is never a security measure. encoding Understanding URL encoding and percent-encoding Why a space becomes %20 in one place and a plus sign in another, how double encoding happens, and why you must never encode a whole URL. encoding Reading exp, iat, and payload claims from a JWT The three-part structure of a JWT, what the standard claims mean, and what to check first when debugging an authentication failure. format When to beautify, minify, or validate JSON The syntax errors that trip people up most often, the large-number precision trap, and which operation fits which situation. convert Unix timestamps: seconds versus milliseconds How to tell 10-digit and 13-digit timestamps apart, the time zone mistake that derails incident analysis, and the Year 2038 problem. convert Common cron expressions and how to check the next run What the five fields mean, a set of expressions worth memorising, and the day-of-month versus day-of-week trap. string camelCase, snake_case, and kebab-case in practice Which convention belongs where, how to handle a project that needs several at once, and why acronyms cause trouble. web HTTP status codes 404, 500, 502, and 503 explained How the code classes narrow down an investigation, the real causes behind common errors, and the difference between 401 and 403, 502 and 504.