Andrew Castor
Infrastructure & Cloud Security Engineer
Summary
I build secure, offline-first systems for environments where reliability isn't optional — healthcare clinics in austere field conditions, multi-site networks, and hardened Linux deployments. Currently shipping a self-hosted EMR for a Costa Rica medical mission and preparing for cleared defense work.
Experience
Tech Operations Lead
2023 – PresentMedical Missionaries of Divine Mercy·Houston, TX
- Led end-to-end EMR modernization using OpenEMR on a hardened Linux/Apache/MariaDB/PHP stack, replacing 20+ years of paper-based workflow across six clinical stations.
- Migrated a corrupted Windows XAMPP environment to Ubuntu 22.04 on VirtualBox with private CA-issued TLS certificates, UFW firewall, and daily cron-based backups with 30-day rotation.
- Designed and deployed a 50,000 sq ft Wi-Fi 6 mesh network spanning five buildings with segmented VLANs, DHCP/DNS, and offline-tolerant routing.
- Implemented RBAC, ACLs, TLS/HTTPS encryption, and least-privilege access controls; engineered secure cloud archival pipeline via Microsoft Entra ID and SharePoint.
- Conducted workflow discovery across Registration, Triage, Medical, Dental, Vision, and Pharmacy departments; trained 50+ end users.
- Costa Rica Field Deployment (April 2026): deployed offline LAN running OpenEMR + OpenMRS in austere, no-internet environment supporting full-cycle traveling clinic operations.
Technical Skills
Ubuntu Server · Apache · Nginx · MariaDB · MySQL · VirtualBox · Wi-Fi 6 Mesh · LAN/WAN · Netplan · DHCP/DNS
Private CA · OpenSSL · TLS · HTTPS hardening · UFW · iptables · RBAC · ACLs · Entra ID · Least Privilege · HIPAA-aligned posture
Azure · Entra ID · SharePoint sync · AWS (learning) · Bash · Cron · PowerShell · Git · GitHub
PHP 8.1 · Python · SQL · MariaDB · OpenEMR · LBF · HL7 (planned) · TensorFlow Lite
Certifications
Education
University of Central Florida
Fall 2026 – Expected 2030B.S. Information Technology (CECS) — Accelerated M.S. Cyber Security & Privacy Track
Houston Community College
Conferred 2025A.A.S. Artificial Intelligence — National Honor Society
GPA: 3.8