Blog

Blog

KEYDAL blog: what we learn in the field on hosting, domains, servers, security, software and press law; step-by-step guides and current notes.

Software

Tailwind CSS v4: Oxide Engine, CSS-First Config and Migration Guide

What is new in Tailwind CSS v4 — Oxide engine speedups, @theme directive, container queries, CSS-first config and migrating from v3.

April 21, 2026 · 11 min read
Software

Tailwind CSS from Scratch: Build Modern UIs with Utility-First

Install Tailwind, learn the utility-first mindset, responsive design, dark mode, custom themes and component extraction — a complete starter guide.

April 21, 2026 · 15 min read
Software

SQL Query Optimization: JOIN Strategies, Subqueries and Index Usage

Speed up slow SQL queries — read EXPLAIN output, understand JOIN types, apply index strategies, compare subqueries and CTEs with examples.

April 21, 2026 · 16 min read
Security

SQL Injection: How It Works and How Parameterized Queries Stop It

The mechanics of classic, blind, time-based and union-based SQL injection, plus how prepared statements and ORMs shut them down for good.

April 21, 2026 · 13 min read
Software

What Is Software Development? Processes, Methodologies, and Tools

What software development is, which methodologies (Agile, Scrum, Waterfall) fit, and which languages and tools you need. A beginner-friendly guide.

April 21, 2026 · 14 min read
API

REST API Security Guide: Authentication, Rate Limiting, and Best Practices

API security with JWT, OAuth2, rate limiting, input validation, CORS, and HTTPS. A practical walkthrough of the OWASP API Security Top 10.

April 21, 2026 · 14 min read
Software

Redis Fundamentals: Cache, Pub/Sub, Session Store and Persistence

Redis use cases in production — cache, session store, rate limit, queue, pub/sub, persistence (RDB/AOF) and cluster architecture.

April 21, 2026 · 14 min read
Hosting

Prometheus and Grafana Server Monitoring: Metric Collection Guide

Set up production-grade monitoring with Prometheus metrics, Grafana dashboards, node_exporter, Alertmanager and PromQL queries.

April 21, 2026 · 14 min read
Software

PostgreSQL Performance Optimization: Indexes, EXPLAIN, and Tuning Guide

PostgreSQL query optimization with EXPLAIN ANALYZE, indexing strategies, connection pooling, and vacuum/autovacuum tuning for production workloads.

April 21, 2026 · 15 min read
Hosting

Plesk Panel Management: Domains, Databases, Email and SSL

Complete Plesk guide — add domains, create databases, set up mailboxes, install Let's Encrypt SSL and harden security from A to Z.

April 21, 2026 · 16 min read
Software

Playwright End-to-End Testing: Modern Browser Automation

End-to-end testing with Playwright — selector strategies, fixtures, trace viewer, parallel testing, CI integration and a Cypress comparison.

April 21, 2026 · 12 min read
Security

Password Hashing: bcrypt, argon2id and scrypt Compared

Modern password hashing — bcrypt, argon2id and scrypt compared, salt, pepper, work factor tuning and Node.js / Python implementations.

April 21, 2026 · 11 min read
Security

OWASP Top 10 2026: Web Application Risks and How to Prevent Them

A walkthrough of the OWASP Top 10 2026 — Broken Access Control, Injection, Cryptographic Failures, SSRF and more, with practical mitigations.

April 21, 2026 · 20 min read
Software

OpenTelemetry Distributed Tracing: Microservice Observability

Distributed tracing with OpenTelemetry — spans, trace context, auto-instrumentation, Jaeger and OTLP export setup guide.

April 21, 2026 · 13 min read
Security

OAuth 2.0 and OIDC: Secure Auth with the Authorization Code Flow

OAuth 2.0 and OpenID Connect — authorization code flow, PKCE, scopes, refresh tokens and a guide to integrating social login.

April 21, 2026 · 14 min read
Software

Node.js Performance: Event Loop, Memory Leaks and Clinic.js Profiling

Optimising Node.js performance — the event loop, blocking operations, memory leak detection, Clinic.js profiling and benchmarking.

April 21, 2026 · 17 min read
Software

Node.js Cluster and PM2 in Production: Zero-Downtime Deploys

Cluster mode, PM2 process manager, zero-downtime reload, log management, monitoring and ecosystem.config.js — a production Node.js guide.

April 21, 2026 · 14 min read
Hosting

Nginx vs Apache: Which One Should You Choose and When

Compare Nginx and Apache HTTP server — architecture, performance, configuration model, .htaccess, modules and which one fits which scenario.

April 21, 2026 · 9 min read
Hosting

Nginx Configuration: Reverse Proxy, Cache and Rate Limiting

Practical Nginx recipes for reverse proxy, FastCGI cache, proxy_cache, limit_req, gzip, HTTP/2 and SSL — with production-ready examples.

April 21, 2026 · 18 min read
Software

Next.js 15 App Router: Server Components, Streaming and Parallel Routes

Master the Next.js 15 App Router — React Server Components, streaming, Suspense, parallel and intercepting routes, server actions and modern React.

April 21, 2026 · 17 min read
Software

MySQL vs PostgreSQL: Data Model, Performance and Scenario Comparison

Compare MySQL and PostgreSQL — data types, ACID, JSON support, performance, replication and which scenarios fit which database.

April 21, 2026 · 13 min read
SEO

Local SEO: Google Business Profile, Local Keywords and Backlinks

Local SEO guide — Google Business Profile setup, local keyword research, NAP consistency, local backlinks and review strategy.

April 21, 2026 · 13 min read
Hosting

Linux Server Administration Basics: SSH, Firewall, Cron, and Service Management

SSH key authentication, UFW/iptables firewall rules, systemd service management, cron scheduling, and the core Linux commands every admin should know.

April 21, 2026 · 13 min read
Hosting

Free SSL with Let's Encrypt: Certbot, Auto-Renewal and Wildcard Certs

Install Let's Encrypt SSL certificates end-to-end — Certbot, auto-renewal, wildcard certificates, DNS challenge and Nginx/Apache integration.

April 21, 2026 · 10 min read
Hosting

Kubernetes Basics: Pods, Deployments, Services and Ingress

Kubernetes fundamentals — Pod, Deployment, Service, Ingress, ConfigMap, Secret, autoscaling and essential kubectl commands for getting started.

April 21, 2026 · 18 min read
Security

JWT Security Pitfalls: alg:none, Weak Secrets, JKU Attack and How to Defend

JSON Web Token security issues — alg:none, weak secrets, JKU/X5U injection, algorithm confusion and the controls that make JWT safe.

April 21, 2026 · 14 min read
Software

Jest Unit Testing: Mocks, Spies, Coverage and Test Driven Development

JavaScript/TypeScript unit testing with Jest — describe/it, matchers, mocks, spies, async tests, snapshots and coverage.

April 21, 2026 · 13 min read
Security

HTTPS and TLS 1.3: Modern Web Encryption and Performance

HTTPS and TLS 1.3 — handshake tuning, cipher suite selection, HSTS, OCSP stapling, an SSL Labs A+ score and performance.

April 21, 2026 · 12 min read
SEO

How Search Engines Work and How to Do SEO: A Complete Guide

What a search engine is, how Google crawls and ranks pages, how to run SEO analysis, and how keyword research really works.

April 21, 2026 · 15 min read
API

GraphQL vs REST: Which API Style Should You Pick and When

Compare GraphQL and REST — query/mutation, the N+1 problem, caching, subscriptions, over-fetching and which scenario each one fits.

April 21, 2026 · 12 min read
Software

GitHub Actions CI/CD: Node.js Workflows, Deploys and Docker Builds

Write GitHub Actions workflows — Node.js tests, Docker builds, SSH deploys, secret management and matrix strategy for a complete CI/CD pipeline.

April 21, 2026 · 15 min read
Hosting

Protecting SSH from Brute Force with Fail2ban: Install and Configure Jails

Install Fail2ban, configure the SSH jail, write custom jails, tune ban times and monitor logs — a practical Linux server security guide.

April 21, 2026 · 11 min read
Software

Express.js Middleware Pattern: Authentication, Logging and Error Handling

The Express middleware architecture — authentication, authorization, logging, error handling and writing your own, with production-grade Node.js examp

April 21, 2026 · 12 min read
Hosting

Essential Linux Server Commands Every Administrator Should Know

The most-used commands in Linux server administration: file operations, system and resource monitoring, networking.

April 21, 2026 · 10 min read
Hosting

Elastic Stack (ELK): Log Analysis with Elasticsearch, Logstash and Kibana

Centralized log management with the ELK Stack — Elasticsearch, Logstash, Kibana and Filebeat setup, index management and log search.

April 21, 2026 · 13 min read
SEO

E-commerce SEO: Product Pages, Schema Markup and Category Strategy

E-commerce SEO guide — product page optimization, Product schema, category pages, faceted navigation, canonical URLs and managing duplicate content.

April 21, 2026 · 15 min read
Hosting

What Is a Domain? Domain Registration, WHOIS Lookup, and TLD Guide

What a domain name is, how to buy one, how to run a WHOIS lookup, and the differences between .com, .net, .org, and country-code TLDs. A complete guid

April 21, 2026 · 14 min read
Hosting

Docker Compose: Multi-Service Architecture and Production Deployment

Build multi-container apps with Docker Compose — web, DB, cache and reverse proxy services, network and volume management, production best practices.

April 21, 2026 · 14 min read
SEO

What Is Digital Marketing? Channels, Strategies, and a Beginner Guide

What digital marketing is, which channels (SEO, Google Ads, Meta Ads, email) to use, and how to build a strategy. A practical guide for SMBs.

April 21, 2026 · 13 min read
Hosting

Deploying Applications with Docker: From Scratch to Production

Dockerfile authoring, multi-stage builds, docker-compose, container networking, volume management, and production deployment best practices.

April 21, 2026 · 16 min read
Security

Multi-Layer DDoS Protection with Cloudflare and Nginx

DDoS attack types (L3/L4/L7), Cloudflare WAF, Nginx rate limiting, Fail2ban and application-level defences — the full stack.

April 21, 2026 · 15 min read
Software

Database Backup Strategies: Full, Incremental, PITR and the 3-2-1 Rule

Design a production backup plan — full vs incremental, Point-in-Time Recovery, the 3-2-1 rule and practical examples for MySQL and PostgreSQL.

April 21, 2026 · 12 min read
SEO

Page Speed and Core Web Vitals 2026: Optimizing LCP, INP, and CLS

A practical guide to Google Core Web Vitals: LCP, INP, and CLS. Improve Lighthouse scores with lazy loading, font optimization, and CDN delivery.

April 21, 2026 · 12 min read
API

API Rate Limiting: Token Bucket, Sliding Window and Redis Implementation

API rate limiting algorithms — fixed window, sliding window, token bucket, leaky bucket and distributed implementation with Redis.

April 21, 2026 · 12 min read
Hosting

Ansible Server Automation: Playbooks, Roles and Inventory

Agentless server management with Ansible — playbooks, roles, inventory, vault, idempotent tasks and a full setup-automation guide.

April 21, 2026 · 13 min read
Software

Advanced TypeScript: Generics, Utility Types and Conditional Types

Advanced TypeScript — generics, utility types (Partial, Pick, Omit, Record), conditional types, infer, template literal types and mapped types.

April 21, 2026 · 16 min read
Software

Advanced Git: Rebase, Cherry-pick, Bisect, and Stash in Practice

Rebase vs merge, interactive rebase, cherry-pick, bug hunting with bisect, stash management, and recovery with reflog. Advanced Git workflow guide.

April 21, 2026 · 11 min read
Hosting

Connecting to a Server with SSH: Key-Based Authentication

What is SSH and how do you connect to a server? Connecting with a password and an SSH key, secure configuration and fixing common SSH errors.

April 20, 2026 · 9 min read