Developer Tutorials

Practical guides — with free browser tools so you can try concepts immediately.

Implementing JWT Authentication in Node.js: From Zero to Secure

Build JWT authentication in Node.js from scratch: login endpoint, token generation, protected route middleware, refresh token pattern, and the security settings that matter.

Apr 9, 2026

JWT Security Pitfalls Every Developer Should Know

The alg:none attack, weak secrets, sensitive data in payloads, and missing exp validation — the JWT security mistakes that get applications breached, with fixes for each.

Apr 4, 2026

Debugging JWT Authentication Errors: A Developer's Field Guide

TokenExpiredError, invalid signature, jwt malformed — the 5 most common JWT errors in Node.js explained, with exact causes, fixes, and how to diagnose each using a token decoder.

Mar 28, 2026

JWT Explained: What's Actually Inside a JSON Web Token

A JSON Web Token has three base64url-encoded parts: header, payload, and signature. Here's what each section means, what every claim does, and why JWTs are signed but not encrypted.

Mar 17, 2026

Why REST APIs Use Unix Time (and How to Convert It in Any Language)

Stripe, GitHub, and Slack all return Unix timestamps in their APIs. Here's why — and how to convert epoch time in JavaScript, Python, and Go with copy-paste snippets.

Mar 6, 2026

Working with Unix Timestamps in Python: datetime, arrow, and beyond

Convert epoch timestamps in Python using datetime, pytz, and arrow — with timezone-safe patterns, pandas support, and pitfalls every developer hits.

Feb 23, 2026

Debugging Unix Timestamps in JavaScript: A Practical Guide

Five common Unix timestamp bugs in JavaScript — wrong year, Invalid Date, timezone drift, float loss, double-conversion — with exact fixes for each.

Feb 12, 2026

Unix Timestamps Explained: What Every Developer Should Know

What epoch time is, why Stripe, GitHub, and Slack use Unix timestamps in every API, and how to convert seconds vs milliseconds — free browser tool included.

Feb 1, 2026