Senior IT Systems Administrator and Embedded Hardware Engineer

David Rosales

Las Vegas, NV

Phone: 702-***-****

Email: ******.****@*****.***

GitHub: github.com/TheHackersWorkshop

PROFESSIONAL SUMMARY

Senior IT Systems Administrator with over 15 years of hands-on experience supporting enterprise Windows and Linux environments. Strong background in Windows Server (2012r2–2022), Active Directory, VMware virtualization, backup and disaster recovery, security patching, and infrastructure automation. Proven Tier II/III support professional known for maintaining high-availability systems, improving operational efficiency through scripting, and delivering reliable, service-focused IT support in fast-paced environments. CORE TECHNOLOGIES

Windows Server 2012r2, 2016, 2019, 2022

Active Directory, Group Policy, DNS, DHCP

VMware ESXi, vCenter, Hyper-V, Proxmox

Microsoft 365, Exchange Online

Linux (Ubuntu, Debian, CentOS)

Backup & Disaster Recovery Planning

SAN / NAS Storage Technologies

Network Security & Patch Management

PowerShell, Python, Bash

Tier II / Tier III End-User Support

Ticketing & IT Service Management Systems

PROFESSIONAL EXPERIENCE

Senior Systems Engineer / IT Administrator

Reimagined Innovations LLC Las Vegas, NV

03/2022 – 03/2025

Administered and maintained mixed Windows and Linux server environments supporting development, testing, and production workloads.

Designed and implemented secure network services including Active Directory, VPN access, DNS, and DHCP.

Managed virtualization platforms using VMware and Proxmox, including system upgrades, performance tuning, and availability planning.

Developed automation scripts using Python and Bash to streamline system monitoring, diagnostics, and maintenance tasks, reducing manual administrative effort. Implemented backup and recovery procedures and conducted routine verification testing to ensure business continuity.

Applied operating system updates, security patches, and vulnerability remediation across all managed systems.

Created and maintained system documentation, operational procedures, and internal IT standards. Systems Administrator / Technical Lead

The Hackers Workshop LLC Las Vegas, NV

07/2020 – 10/2021

Supported and maintained Windows and Linux systems used for development, training, and production environments.

Managed user accounts, permissions, and access controls using directory services and system-level security tools.

Provided Tier II support for hardware, operating system, and network-related issues. Built internal tools and scripts to automate repetitive administrative tasks and improve response times.

Maintained version control repositories and deployment workflows using Git-based tooling. IT Administrator / Systems Engineer

Confidential Client (Long-Term Contract)

04/2009 – 12/2019

Supported enterprise IT infrastructure across Windows Server and Linux environments, maintaining 99.9% system uptime.

Administered Active Directory domains, user/group policies, DNS, and DHCP services. Managed VMware-based virtualized environments, including provisioning, monitoring, and troubleshooting.

Performed system hardening, patch management, and compliance-driven security updates. Coordinated backup, disaster recovery planning, and restoration testing. Served as escalation point for Tier II/III issues and mentored junior technical staff. Collaborated with stakeholders to modernize infrastructure and integrate new technologies into production systems.

Network Administrator

VM Direct

05/2000 – 12/2006

Administered enterprise Windows network infrastructure supporting over 5,000 users. Managed Active Directory, DNS, and network services. Reduced downtime through proactive hardware upgrades and system maintenance. Assisted with network security initiatives and incident response efforts. Owner / Field Technician

ECR Networks

09/1994 – 04/2009

Provided IT and network support services to residential and small business clients. Installed, configured, and maintained Windows and Linux systems. Delivered on-site troubleshooting, system optimization, and customer training. NOTABLE ACHIEVEMENTS

Issued U.S. Patent No. 12,351,126 (2025) for a hardware-based security detection system deployed in real-world environments.

Developed multiple open-source administrative tools used for monitoring, diagnostics, and automation across Linux systems.

TECHNICAL PROJECTS & AUTOMATION

Authored Python and Bash scripts to automate system health checks, permission auditing, and service control.

Created reusable Linux command frameworks to improve administrative efficiency across environments.

Built terminal-based monitoring and diagnostic tools for system administrators. EDUCATION & CERTIFICATIONS

CompTIA A+ Certification (2000)

Formal coursework in Java Programming

Continuous professional development in Windows Server, Linux administration, networking, and security

OPEN SOURCE

GitHub: github.com/TheHackersWorkshop

Includes system monitoring tools, network diagnostic utilities, automation scripts, and command-line administrative frameworks.

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