Built for the Field.
Hardened. Recoverable. Offline-first.
Andrew Castor
Infrastructure & Cloud Security Engineer
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.
org: "MMDM (volunteer)"
stack: [linux, tls, rbac]
clearance: "eligible"
travel: "50–80% ok"
MMDM OpenEMR — Offline-First Clinical Platform
In Production · Field Deploy 2027Medical Missionaries of Divine Mercy · Houston → Costa Rica · 2024–Present
Self-hosted EMR built to run a six-station volunteer clinic in a Costa Rican parish hall with no internet, no cloud, and no public DNS. Migrated off a corrupted XAMPP environment to a hardened Ubuntu / Apache / MariaDB / PHP stack with a private certificate authority, daily backups, and bilingual Spanish/English clinical forms.
0
Clinical Stations
0
Intake Delay ↓
0
Users Trained
0
Internet Required
Problem
Corrupted Windows XAMPP stack with Aria storage engine failure. Paper forms across six clinical stations. No backups, no encryption, no recovery path. Mission-critical with zero connectivity guarantee.
Solution
Clean rebuild on Ubuntu 22.04 + Apache + MariaDB 10.6 + PHP 8.1. Private CA for offline TLS. UFW-hardened LAN posture. Daily cron backups with 30-day rotation. VirtualBox snapshot recovery.
Impact
Replaced 20+ years of paper workflow with structured clinical data. HIPAA-aligned posture. Recoverable from hardware failure. Designed for volunteers to redeploy at any mission site without a network engineer present.
What I Work With
Certifications
Additional Projects
Network Architecture
Deployed50,000 sq ft Wi-Fi 6 Mesh
Multi-building Wi-Fi 6 mesh across five buildings for MMDM Houston ops center. Segmented VLANs, DHCP/DNS, offline-tolerant routing.
Embedded / IoT
ShippedEmergency Evacuation Guidance Device
ENGR 1201 · University of Houston · Spring 2026
Handheld device that computes real-time evacuation routes via Dijkstra's algorithm, rerouting users away from heat sources detected by distributed DS18B20 probes. Raspberry Pi 4 + ESP32 sensor hub over USB-serial.
AI / Edge
PrototypeFall Detection System
Real-time emergency detection model on TensorFlow Lite + Raspberry Pi with mobile alert integration. Edge inference, no cloud round-trip.
NLP / ML
CompleteNewsBot 2.0
NLP pipeline for news article classification, sentiment analysis, and multilingual translation.
Security Lab
In ProgressSplunk SOC Home Lab
Self-hosted Splunk environment for log ingestion, detection rule writing, and SOC triage exercises. Pairs with TryHackMe SOC L1 path.
Build systems that hold up.
I'm open to infrastructure, security, and field deployment roles — full-time, contract, or co-op. Relocating to Orlando, FL in August 2026 for UCF.