Articles & Guides
Useful resources for web developers and system administrators
Performance
What Is a HAR File? Record, Read and Sanitize It
A HAR file is a JSON log of a browser tab's network requests. Record one in Chrome, Firefox, Edge or Safari and strip cookies and tokens before sharing.
Networking
Subnet Mask Chart: /8 to /32 CIDR Table with Host Counts
Subnet mask chart /8 to /32: 255.255.255.0 is /24 with 254 hosts, 255.255.0.0 is /16. How to calculate a mask and find yours on Windows, Mac, Linux.
Security
Advertising Disclosure: What Counts as an Ad and erid Basics
What counts as advertising on a website, who is responsible for the label, where the erid token goes, and which technical mistakes leave a live page unlabelled.
Monitoring
Yandex Metrica and Session Recording: Setup and Privacy
How to set up the Metrica counter and session recording: where the code goes, why recordings and goals fail, the effect on page speed, and the privacy obligations.
Domains
Connect a Domain to Tilda: A Record, CNAME and SSL Fixes
Connect your own domain to Tilda: the A record at the registrar, the domain in project settings, why SSL is not issued yet and how to verify it.
Infrastructure
The .htaccess File: Redirects, Access and Caching
What .htaccess is, where the file lives and how it works: directive syntax, HTTPS and www redirects, IP and password access, caching headers and 500 error fixes.
Infrastructure
Website Backup: What to Copy and How to Verify Restores
A complete website backup: files, database, configs, cron and certificates. The 3-2-1 rule, RPO and RTO, mysqldump flags, encryption, restic and restore testing.
Infrastructure
VPS Initial Setup: The First 30 Minutes Before Deploy
Step-by-step VPS setup: LTS choice, sudo user, SSH keys, ufw and fail2ban, updates, swap, time sync, limits. Real commands and how to verify each step.
SEO
Title and Meta Description Tags: How to Write and Check Them
How to write title and meta description tags: length in pixels, formulas and templates by page type, how to inspect yours and a competitor's, common mistakes.
Security
SSH Key Authentication: Setup, authorized_keys, No Passwords
Set up SSH key login: ssh-keygen -t ed25519, ssh-copy-id, 700/600 permissions, PasswordAuthentication no, and fixes for Permission denied (publickey).