Blog

Articles about reverse engineering, security, DevOps and web development by Rafael Cavalcanti da Silva.

· 20 min read

SEO Case Study: From zero to Google's top — Part 2: Execution, tools and first results

Documenting the execution phase: automated ranking monitoring tools (Puppeteer + MongoDB), keyword expansion from 10 to 55, on-page optimizations, and cyber security strategy — with real code and measured results.

#seo#google#astro#puppeteer#mongodb#cyber-security#case-study#ranking
· 45 min read

Breaking 9 layers of DexProtector: Real-world reverse engineering of an Android banking app

Advanced reverse engineering analysis of a mobile banking app protected by DexProtector with 9 layers: encrypted DEX, ~2000 enc!5016 strings, JNI dispatch with 148 overloads, dynamic RegisterNatives, TEA-like stream cipher, ARM64 emulation with Unicorn, memory-only .so dump, ALICE anti-fraud bypass — all documented with real code and results.

#reverse-engineering#frida#android#jni#dexprotector#unicorn#arm64#capstone#banking#security#cyber-security#pentesting
· 25 min read

SEO Case Study: From zero to Google's top — Part 1: Diagnosis, tech stack and first steps

Real-time series documenting the process of ranking 'Rafael Cavalcanti da Silva', 'rafael cavalcanti', 'rafael' and 'root' on Google — using Astro, Nginx, Google Analytics 4, Search Console and advanced technical SEO techniques.

#seo#google#astro#nginx#analytics#case-study#ranking
· 30 min read

Real-world Linux Server Hardening: 14 layers I apply in production with automation code

Advanced Linux hardening guide based on real infrastructure: SSH hardening + fail2ban + UFW + kernel sysctl + auditd + systemd sandboxing + nginx auto-fix + Redis bind + MongoDB auth + Postfix secure relay + automated backup with Google Drive + orchestrated restore via Go + Conky monitoring — all with production scripts and configs.

#security#cyber-security#linux#hardening#devops#defensive#nginx#systemd#automation
· 28 min read

NGINX in real production: Reverse proxy, auto-fix, multi-upstream, SSL automation and Go deploy with systemd hardening

Advanced NGINX configuration based on real infrastructure: 4 simultaneous upstreams, auto-detection of missing configs, iterative error fix, zone-based rate limiting, Go-generated nginx configs, SSL with certbot + self-signed fallback, systemd sandboxing, graceful shutdown in Go, WebSocket proxy and monitoring — all from production.

#nginx#go#golang#devops#deploy#systemd#ssl#automation#security#hardening