Paul Ispas · rojackal
CTO and Infrastructure Engineer Specializing in Linux, Networks and Automation
I am Paul Ispas, known online as rojackal. As Chief Technical Officer at HPRO Group Limited, I design, operate and improve the infrastructure behind proxy services, VPN platforms, billing systems, automation tools and production websites.
My work is hands-on and results-driven: maintaining stable servers, improving performance, strengthening security, automating repetitive operations and resolving complex production problems at their root cause.
About me
Built around real production infrastructure
I have extensive experience with Linux server administration, web hosting, proxy networks, VPN systems, automation, billing platforms and performance optimization. My focus is on building technical systems that remain reliable, maintainable and useful under real operating conditions.
I prefer proven technology, understandable configurations, useful logging and direct troubleshooting. Infrastructure must be documented, recoverable and maintainable by the people responsible for it. In most cases, simple and stable beats fashionable and complicated.
Professional experience
Technical leadership backed by hands-on work
Current role
Chief Technical Officer
HPRO Group Limited
I lead technical work involving server infrastructure, proxy and VPN services, WHMCS automation, web performance, security hardening, payment integrations, monitoring and operational improvement.
The role combines infrastructure engineering and system administration with technical planning, service development and business-critical troubleshooting.
Visit HighProxies.comInfrastructure operations
Linux servers, networking, DNS, firewalls, TLS, web services, monitoring, automation and production incident resolution.
Proxy and VPN systems
HTTP and SOCKS5 proxy services, VPN infrastructure, IP allocation, authentication, abuse prevention and service reliability.
Web and billing platforms
WordPress, WHMCS, PHP applications, customer portals, payment integrations, automation hooks and administrative workflows.
Technical skills
Core areas of expertise
A practical technical stack developed through operating, maintaining and troubleshooting live services.
Linux and server administration
- Rocky Linux and RHEL-based systems
- Systemd services, journals and diagnostics
- Bash scripting and server automation
- Package builds and RPM workflows
- Backup, recovery and maintenance
Web stack and performance
- NGINX configuration and optimization
- PHP-FPM and OPcache tuning
- MySQL and MariaDB administration
- Redis and application caching
- HTTP/2, HTTP/3, Brotli and TLS
Proxy, VPN and networking
- HTTP, HTTPS and SOCKS5 infrastructure
- Dedicated IP and subnet management
- WireGuard, OpenVPN and IKEv2
- Firewalling with nftables
- Authentication and access control
WHMCS and automation
- WHMCS modules, hooks and APIs
- Service provisioning workflows
- Payment gateway integrations
- Customer portal improvements
- Operational and administrative tools
Security and reliability
- Linux and application hardening
- Firewall rules and access restrictions
- mTLS and certificate management
- Fraud and abuse prevention
- Monitoring and incident analysis
Web, SEO and analytics
- WordPress technical maintenance
- Technical SEO and crawlability
- Analytics and conversion tracking
- Landing-page optimization
- Core Web Vitals and website speed
How I work
Practical, direct and accountable
I do not add complexity simply because a tool is fashionable. Good infrastructure should be stable, documented, monitored and repairable. My approach is to understand the failure, correct its root cause and leave the system in better condition than before.
This website
Technical notes from real operational work
This is my personal space for technical notes, opinions, lessons learned and practical guides. I write about Linux, NGINX, MariaDB, WHMCS, proxy infrastructure, VPN systems, security, automation, SEO and the business of operating online services.