Blog & Learn
Practical developer guides written to actually answer the question. No 1500-word intros, no SEO padding — just the part you came for.
Base64 encoding across 5 languages: JavaScript, Python, Go, Rust, PHP
Idiomatic Base64 and Base64URL encoding/decoding in JS, Python, Go, Rust, and PHP — with the standard-library one-liners and the gotchas each language buries.
- Encodinghashingsha256hmac
Hashing in 2026: SHA-256, HMAC and PBKDF2 across Node, Python, Go, Rust
Which stdlib function to reach for, which library to avoid, and the one-liner that gets you SHA-256 + HMAC-SHA256 in each of the big runtimes.
Apr 27, 2026 · 1 min readRead - Developeruuidjavascriptpython
Generating UUIDs across languages: stdlib vs libraries in 2026
v4 and v7 in JavaScript, Python, Go, Rust and PHP — which ships in the standard library, which needs a package, and the one-liner that works today.
Apr 27, 2026 · 1 min readRead - Cheatsheethttpcheatsheetapi
HTTP status codes: the only reference you'll need
Every HTTP status code with plain-English meaning — when to send which, when to care about the distinction, and the codes you can usually ignore.
Apr 27, 2026 · 3 min readRead - Cheatsheetiso8601datescheatsheet
ISO 8601 date format cheatsheet: every variant with examples
The only date format you should be storing and serialising in 2026. Every shape, the pitfalls, and the quick reference for parsing.
Apr 27, 2026 · 2 min readRead - Encodingwebhookshmacsecurity
How to verify webhook signatures: Stripe, GitHub, Slack
Every major webhook provider signs their requests with HMAC. Here's the working verification code for each, the timing-attack pitfall everyone hits, and a universal template.
Apr 27, 2026 · 1 min readRead - Developerregexperformancesecurity
Why your regex is slow: catastrophic backtracking explained
The reason `(a+)+b` hangs on `aaaaaaaaac` — and the five patterns that turn a 10ms validator into a 30-second ReDoS attack.
Apr 27, 2026 · 2 min readRead - Datacsvdataexcel
CSV parsing is harder than you think (and why `split(',')` isn't enough)
Quoted fields, escaped quotes, embedded newlines, UTF-8 BOMs, Excel's opinions. A tour of every CSV footgun and the libraries that handle them.
Apr 27, 2026 · 2 min readRead - Datajsonjavascriptpython
NaN, null and undefined in JSON: what serialises to what
JSON has null. JavaScript has null, undefined and NaN. Python has None. This is the table of what survives each conversion — and the traps everyone hits.
Apr 27, 2026 · 2 min readRead - Developertimezonesdatetimedst
Timezone conversion: the edge cases that bite
DST, half-hour offsets, timezones with historical changes, and the midnight that doesn't exist. If your code assumes 24 hours a day, it's wrong.
Apr 26, 2026 · 6 min readRead - Financefloating pointfinancejavascript
Why 0.1 + 0.2 !== 0.3 (and what to do with money)
IEEE-754 explained in 500 words, why every language does this, and the three correct ways to handle currency.
Apr 26, 2026 · 4 min readRead - Encodingpasswordsecurityentropy
How to generate a strong password (and what entropy means)
Length beats complexity. Here's the math, the actual number of bits you need, and why `correct horse battery staple` is stronger than `P@ssw0rd!`.
Apr 26, 2026 · 5 min readRead - Encodingbase64urlencoding
Base64URL vs Base64: when the extra characters matter
The + / = characters in standard Base64 break URLs, filenames, and JWT headers. Base64URL is the fix — and it's almost but not quite a drop-in replacement.
Apr 26, 2026 · 3 min readRead - Financecompound interestfinancesavings
Compound interest explained with 5 worked examples
The formula, the intuition, the difference monthly vs yearly compounding makes, and why time matters more than rate.
Apr 25, 2026 · 6 min readRead - Designoklchcolorcss
OKLCH for designers: why switch from HSL
HSL's saturation and lightness lie to you. OKLCH doesn't. Here's what you gain in 5 minutes of learning a new syntax.
Apr 25, 2026 · 5 min readRead - Designimagespngjpg
PNG vs JPG vs WebP: pick the right image format in 2026
WebP wins most of the time now. Here's when to still reach for PNG (alpha + crisp edges) or JPG (massive photos, universal support).
Apr 25, 2026 · 5 min readRead - Encodinghmacsecuritycrypto
What is HMAC (and why SHA-256 alone isn't enough)?
HMAC is how you prove a message wasn't tampered with. It's SHA-256 plus a clever wrapping you should never try to reinvent.
Apr 25, 2026 · 5 min readRead - Cheatsheetcroncheatsheetscheduling
Cron schedule cheatsheet: 50 patterns with explanations
Copy-paste cron expressions for every common cadence — every minute, every night, every weekday, every quarter, business hours only, and 45 more.
Apr 25, 2026 · 5 min readRead - Developeruuididsdatabase
UUID v4 vs v7: which should you use in 2026?
v4 is random. v7 is time-sortable. Here's what that means for your database, your caches, and whether you can stop using auto-increment IDs.
Apr 24, 2026 · 5 min readRead - Cheatsheetregexcheatsheetpatterns
Complete regex cheatsheet (with copy-paste patterns that actually work)
Every metacharacter, every flag, and 30 real-world patterns for email, IP, date, URL, slug, credit-card and more. All testable in the browser.
Apr 24, 2026 · 8 min readRead - Datajsonyamlconfig
How to convert JSON to YAML (and back) without breaking things
JSON ↔ YAML looks simple until you hit anchors, multi-line strings, booleans that aren't booleans, and the Norway problem.
Apr 24, 2026 · 5 min readRead - Developercronschedulingunix
Cron syntax explained: a no-nonsense guide
Cron is five fields in a line of text. This is what each one means, what the specials do, and why `0 0 * * 0` runs weekly.
Apr 24, 2026 · 6 min readRead - Encodingencodingbase64fundamentals
Base64 explained: what it is, what it isn't, and when to use it
Base64 is everywhere — emails, JWTs, data URLs, certificates. Here's what it actually does, and what it doesn't (encryption!).
Apr 20, 2026 · 4 min readRead - Datajsonxmldata
JSON vs XML in 2026: which should you actually use?
JSON won the API war — but XML still rules in finance, government, and SOAP. Here's a no-nonsense breakdown of when each makes sense.
Apr 15, 2026 · 5 min readRead - Developerauthjwtsecurity
What is a JWT? A practical guide for developers in 2026
JSON Web Tokens explained simply: what they are, how they work, when to use them — and how to inspect one safely.
Apr 10, 2026 · 6 min readRead