Developer Guides

JSON explained: data types, syntax rules, and why it became the universal data format for APIs and config files.

Understand what makes JSON valid, spot the most common errors, and go further with JSON Schema.

Naming conventions, dates, null vs omit, large numbers, pagination, error responses, and nesting: the conventions that save debugging time.

Why plain JSON mode only guarantees valid syntax, how schema-constrained structured outputs enforce an exact shape, and how OpenAI, Claude and Gemini each implement it.

CSV explained: structure, quoting and escaping rules, delimiters, and why CSV vs JSON is not a lossless conversion.

XML explained: element structure, attributes, well-formed vs valid, XML vs JSON, and where XML is still used today.

YAML explained: indentation-based syntax, scalars, sequences, anchors, and common gotchas like the Norway problem.

TOML explained: tables, arrays of tables, native dates, and why it has no null value or top-level array.

A side-by-side comparison of JSON and YAML: syntax, use cases, and when to choose one over the other.

JSON Schema explained: core keywords, composition, Draft-07 vs 2020-12, and practical validation use cases.

Percent-encoding explained: which characters must be encoded, how it works, and the difference between encodeURI and encodeURIComponent.

Base64 explained: how it works, why it exists, common use cases, and the difference with Base64url.

Markdown explained: why it was created, how plain text becomes HTML, the core syntax, and where it is used today.

A quick reference for all Markdown syntax: headings, emphasis, links, code blocks, tables, task lists, and more.

A quick reference for SQL syntax: clause execution order, joins, filtering, aggregates, and where MySQL, PostgreSQL, SQLite, and T-SQL disagree.

SVG explained: the XML structure behind vector graphics, why viewBox matters, what SVGO actually optimizes, and converting SVG to JSX.

GraphQL explained: queries vs REST, the schema definition language, resolvers, and why over-fetching is the problem it was built to solve.

JSON Web Tokens explained: structure, how they work, common algorithms, and security best practices.

Hash functions explained: one-way digests, MD5 vs SHA-256, use cases, and why you should never hash passwords with SHA.

HMAC explained: why a keyed hash beats a plain one, the ipad/opad construction, and where HS256 shows up in JWTs and webhooks.

Three commonly confused transformations compared: what's reversible, what needs a key, and why Base64 is not encryption.

UUIDs explained: the 5-part structure, v1 vs v4 vs v7 vs ULID, uniqueness guarantees, and when to choose UUID over auto-increment.

How password entropy is calculated, why length matters more than character variety, and why human-invented passwords are weaker than the math suggests.

Regex explained: character classes, quantifiers, anchors, groups, and practical patterns for everyday use.

A quick reference for regular expression syntax: character classes, quantifiers, anchors, lookarounds, flags, and common patterns.

A practical reference for cron syntax: field breakdown, special characters, and ready-to-use schedules.

Unix time explained: the epoch, seconds vs milliseconds, the Year 2038 problem, and why computers store time as a plain integer.

Binary, octal, and hexadecimal explained: how positional counting systems work, why hex maps cleanly to bits, and where each base shows up in real code.

Color formats compared: how HEX, RGB, and HSL represent the same color, transparency, and WCAG contrast ratios for accessible text.

Open Graph explained: the four required properties, how Twitter/X cards fall back to og: tags, and why og:image needs to be an absolute URL.

Minification explained: what CSS, HTML, and JS minifiers actually remove, why JS shrinks the most, and why source maps matter once you minify.

How GPT and other LLMs split text into tokens with Byte Pair Encoding, why token count drives API cost and context limits, and which models you can count offline.