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Regular Expressions: Practical Guide with 20 Ready-to-Use Patterns

A practical regex reference for developers. Covers syntax fundamentals, flags, groups, lookaheads, and 20 real-world patterns for email, URL, IP address, date, phone, password validation and more.

Yesterday Web

JWT Deep Dive: Structure, Algorithms, and Security Pitfalls

A thorough guide to JSON Web Tokens for developers. Covers the three-part structure, signing algorithms (HS256, RS256, ES256), standard claims, and the most common security vulnerabilities to avoid.

Last Saturday Security

Unix Timestamps: The Developer's Complete Guide

Everything developers need to know about Unix timestamps: what they are, why 1970, timezone pitfalls, milliseconds vs seconds, the Year 2038 problem, and code examples in PHP, Python, and JavaScript.

Last Saturday Backend
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