GUIDES & TUTORIALS
Developer Guides
132 articles · tools, technologies, and concepts behind FreeUtil
New Developer Onboarding Checklist: Set Up Your Dev Environment Fast
Everything a new developer or a team needs to set up a fresh development environment — SSH keys, Git config, editor setup, package managers, environment variables, and team conventions.
Tech Stack สำหรับ Startup ไทย: เลือกอะไรดีในปี 2025?
คำแนะนำการเลือก Tech Stack สำหรับ Startup และ SME ไทย ครอบคลุม Frontend, Backend, Database, Hosting,…
How to Write Good Git Commit Messages (With Examples)
Write commit messages that your future self will thank you for — the 50/72 rule, imperative mood, Co…
Production Incident Response: A Developer's Runbook
How to handle production incidents calmly and systematically — detection, triage, communication, inv…
Code Review Checklist: What to Check Before Approving a PR
A practical code review checklist covering correctness, security, performance, readability, testing,…
Website Launch Checklist: 50 Things to Check Before Going Live
A complete pre-launch checklist covering performance, security, SEO, accessibility, cross-browser te…
chmod 755 vs 644: What They Mean and When to Use Each
A clear explanation of the two most common Linux permission sets — what 755 and 644 mean in both oct…
How to Read a Traceroute: Diagnosing Network Problems
Understand traceroute output — what each hop means, reading RTT values, identifying bottlenecks, int…
How HTTPS Works: The TLS Handshake Explained Step by Step
A step-by-step walkthrough of what happens when your browser connects to an HTTPS site — ClientHello…
Authentication vs Authorization: What's the Difference?
Understand the critical difference between authentication (who are you?) and authorization (what can…
What Is Base64 Encoding? When and Why to Use It
Understand Base64 encoding — how the algorithm works, why 3 bytes become 4 characters, common use ca…
What Is a Reverse Proxy? How It Works and Why You Need One
Understand reverse proxies — how they differ from forward proxies, why Nginx is used as a reverse pr…