Developer guides, tutorials, and tips from the team behind BoltKit.
Everything you need to know about Unix file permissions — owner, group, other, octal notation, symbolic notation, and the most common permission presets for files and directories.
Read article →Learn how to read and write cron expressions from scratch. We break down the five-field syntax, special characters, and walk through real-world scheduling examples.
Read article →A practical guide to understanding JSON Web Tokens — how they're structured, how to decode the header and payload, and what to watch out for when working with JWTs in production.
Read article →Learn regular expressions step by step with practical examples — character classes, quantifiers, groups, lookaheads, and real-world patterns for email, IP, dates, and more.
Read article →Understand CIDR notation and IP subnetting from scratch — subnet masks, network ranges, usable hosts, and practical examples from AWS VPCs to Kubernetes pod networks.
Read article →Master JSON formatting, validation, and debugging — syntax rules, common errors like trailing commas and single quotes, command-line tools, and tips for working with JSON every day.
Read article →Learn how Base64 encoding works from the ground up — why it exists, how binary becomes text, the URL-safe variant, common use cases, and why it's not encryption.
Read article →A practical guide to every DNS record type you'll encounter — from A and CNAME to MX, TXT, and SRV. Includes DNS-over-HTTPS and command-line lookup examples.
Read article →Everything you need to know about HTTP status codes — 1xx through 5xx, when to use each in REST APIs, the difference between 401 and 403, and debugging tips.
Read article →Understand Unix epoch time from scratch — what it is, how to convert it, timestamps in different programming languages, the Y2038 problem, and timezone pitfalls.
Read article →