Ruben Arredondo
Senior Systems Administrator Design Engineer
Senior Systems Administrator Design Engineer with 6+ years of progressive IT experience supporting DoD and government environments. I design and operate virtualized infrastructure across classified and unclassified networks, with deep experience in DISA STIG and NIST compliance, full-lifecycle patch management, and mission-critical system deployment.
Experience
Senior Systems Administrator Design Engineer · CACI International
Jun 2023 – Present
Colorado Springs, CO
- Author technical proposals, Bills of Materials (BOMs), and Basis of Estimate (BOE) documentation supporting government contract bids and task order responses for DoD clients.
- Lead infrastructure design and deployment for government projects, producing system architecture documentation and implementation roadmaps for multi-million-dollar contracts.
- Design and deploy virtualized environments using VMware vSphere and ESXi, managing 200+ virtual machines across classified and unclassified networks.
- Oversee full lifecycle patch management for 150+ Windows and Linux servers, remediating critical vulnerabilities in accordance with DoD security requirements.
- Apply DISA STIGs and cyber hardening procedures across enterprise infrastructure, maintaining continuous Authority to Operate (ATO) compliance.
- Monitor system health and endpoint security using SolarWinds, Tanium, and LogRhythm SIEM, ensuring uptime and rapid threat response.
- Develop and execute detailed installation, migration, and rollback plans for infrastructure upgrades.
- Mentor IT personnel on technical standards, troubleshooting methodologies, and DoD security requirements.
Database Administrator I · Columbia Public Schools
Oct 2021 – May 2023
Columbia, MO
- Automated routine database tasks using PowerShell and SQL, increasing efficiency for redundant administrative processes.
- Supported development, test, and staging database environments, ensuring high availability and performance.
- Managed Active Directory user accounts, group policies, and security permissions for educational applications, ensuring compliance with student data privacy regulations.
Technology Support Analyst · Columbia Public Schools
Feb 2021 – Oct 2021
Columbia, MO
- Provided technical support for 5,000+ desktops, laptops, and iPads across the district.
- Evaluated and maintained site-based parts inventory, ensuring timely supply requests and minimizing downtime.
Technology Specialist · North Shore District 112
Jan 2020 – Jan 2021
Highland Park, IL
- Managed hardware and software repairs for student and staff Mac, iPad, and Chromebook devices, supporting 2,000+ users.
- Administered remote management of iOS devices using MDM solutions, deploying applications and security configurations district-wide.
Projects
The Woodworking Bench · Woodworking reference & design platform
thewoodworkingbench.com ↗A public reference and design-sharing platform for woodworkers, built on Next.js and Postgres with authenticated user accounts and OAuth sign-in. Features a 2D sheet-goods cut optimizer using a guillotine bin-packing algorithm with rendered layout output, a species reference library sourced from USDA wood shrinkage data, and a site-wide search index. Built and operated end to end, including auth, database, SEO, and a full security-hardening pass.
- Next.js 15
- TypeScript
- Prisma
- PostgreSQL
- Tailwind
- Vercel
F1T Medical · Client engagement · healthcare practice website
f1tmedical.com ↗Designed, built, and deployed the full website for a chiropractic and wellness practice. Implemented a deliberate HIPAA boundary so the marketing site collects no protected health information, with all patient data handled by the practice's dedicated booking and records system. Built in Florida healthcare-advertising compliance, structured SEO, a rate-limited contact form, dark mode, automated tests, and CI pre-commit hooks. Owned the full infrastructure: hosting, DNS, TLS, and email deliverability.
- Next.js 15
- TypeScript
- Tailwind
- Render
- Cloudflare
- Resend
Self-Hosted Homelab · Personal infrastructure & automation lab
A production-grade home lab used to practice and prove enterprise skills outside of work. Runs containerized services behind a reverse proxy with automated TLS, secure remote access over a private mesh network, and network-wide segmentation. Configuration is codified and version-controlled, with an Ansible framework applying CIS-aligned hardening across SSH, firewall, kernel, and audit controls, and encrypted secrets management.
- Linux
- Docker
- Ansible
- Traefik
- Cloudflare
- WireGuard
Skills
Operating Systems
- Windows Server 2016/2019/2022
- Red Hat Enterprise Linux
- Fedora
- Ubuntu
Virtualization & Cloud
- VMware vSphere / ESXi / vCenter
- Docker
- Podman
- Microsoft Azure
Security & Compliance
- DISA STIGs
- NIST frameworks
- Patch management
- Vulnerability remediation
- ATO compliance
Automation & Scripting
- PowerShell
- Bash
- Ansible
- SQL automation
Monitoring & Management
- LogRhythm SIEM
- SolarWinds
- Tanium
- NetApp storage
Databases & Directory
- Microsoft SQL Server / T-SQL
- Backup & recovery
- Active Directory & Group Policy
- LDAP/S
Professional
- Infrastructure design
- Technical proposals & BOE/BOM
- Project management
- Team mentorship
Certifications
CompTIA Cloud+
CompTIA · Sep 2024
Verify on Credly ↗
CompTIA Security+
CompTIA · Aug 2023 · valid through 2029
Verify on Credly ↗
CompTIA A+
CompTIA · Apr 2023
Verify on Credly ↗
DP-900 Azure Data Fundamentals
Microsoft · Jan 2023
Verify on Credly ↗
SC-900 Security, Compliance & Identity
Microsoft · Nov 2022
Verify on Credly ↗
AZ-900 Azure Fundamentals
Microsoft · Jul 2022
Verify on Credly ↗
Education
M.S. Information Technology Management
2023 – 2024
Colorado State University Global
Specialization: Cybersecurity
B.S. Information Technology
2021 – 2023
Colorado State University Global
Specialization: Project Management
Get in touch
Based in Colorado Springs, CO. Always open to interesting work and good conversations. The best way to reach me is through LinkedIn.