Dennis Johnson
AI Automation & Infrastructure Engineer
Contact: dennis.dev.johnson@gmail.com
About
Results-driven IT Infrastructure leader with 24+ years driving enterprise-scale transformations in healthcare. Deep expertise spanning data center architecture, cloud hybrid environments, security hardening, and team leadership. Builds and mentors high-performing infrastructure teams, fostering growth through career development and structured operational processes. Passionate about leveraging AI and large language models to automate infrastructure operations and engineering workflows.
Experience
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IT Infrastructure Manager at Healthcare Organization
HybridSummary:
- Leading infrastructure team including System Engineers, Administrators, and Cloud Engineers. Defining enterprise infrastructure direction, managing departmental budget, and driving strategic technology partnerships.
Responsibilities:
- Orchestrated physical data center consolidation — reduced from 2 data centers to 1, 8 racks to 2 (75% reduction); implemented Azure hybrid cloud for DR
- Orchestrated enterprise-wide migration from VMware vSphere to Microsoft Hyper-V — consolidated 800 VMs to 350 (56% reduction)
- Orchestrated migration from VMware NSX to Illumio for host-based micro-segmentation and zero-trust security
- Implemented infrastructure security design, vulnerability remediation, and compliance
- Member of Disaster Recovery Team
- Recruit, mentor, and develop a team of engineers and administrators
- Conduct performance reviews, career development planning, and skills gap analysis
- Establish on-call rotation and escalation procedures
- Architect and continuously refine automation pipelines for patching, provisioning, and compliance enforcement
- Evaluate emerging technologies, prototype solutions in lab environments, and drive production implementation
- Define change management and configuration management standards
- Maintain infrastructure documentation library
- Ensure compliance across all infrastructure systems
- Coordinate with auditors during annual security and compliance assessments
- Remediate penetration test findings and risk mitigation plans
- Hyper-V
- Azure
- Illumio
- PowerShell
- Cisco
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IT Infrastructure Architect at Healthcare Organization
On-siteSummary:
- IS design, planning, and architecture across on-premise and cloud infrastructures. Supervision of IT team with guidance on task assignment and resource allocation.
Responsibilities:
- Architected and implemented micro-segmentation with VMware NSX-T
- Architected and implemented vCenter and NSX-T Federation between multiple data centers
- Architected and implemented migration from IBM TSM to Rubrik for disaster recovery
- Architected and implemented automation for security updates and vulnerability remediation via Ansible and Puppet
- Architected and implemented new data center buildout expanding from a single to dual data center environment
- VMware
- NSX-T
- Azure
- Ansible
- Rubrik
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Technical Team Lead at Healthcare Organization
On-siteSummary:
- Led infrastructure team while performing System Engineer duties. Coordinated projects, schedules, and resource procurement across teams.
Responsibilities:
- Served as escalation point for critical infrastructure issues
- Mentored junior engineers and conducted technical knowledge transfers
- Led troubleshooting efforts on complex, cross-platform outages
- Managed project timelines, deliverables, and resource allocation across concurrent initiatives
- Translated business requirements into technical designs and implementation plans
- Drove vendor evaluations and proof-of-concept testing for new technologies
- Maintained system uptime and SLA targets across production infrastructure
- Coordinated change management and maintenance windows
- Developed standard operating procedures for recurring operational tasks
- Acted as technical liaison between engineering team and senior leadership
- Balanced hands-on engineering work with team oversight and project delivery
- VMware
- Cisco UCS
- Windows Server
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Systems Engineer at Healthcare Organization
On-siteSummary:
- Core infrastructure engineer responsible for virtualization, storage, networking, and messaging platform migrations.
Responsibilities:
- Executed VMware vSphere upgrades across three major versions (4.1 → 5.x → 6.0)
- Executed compute platform migration from IBM Blade Center to Cisco UCS
- Executed three-generation Exchange migration (2003 → 2010 → 2016)
- Executed multi-phase SAN modernization: IBM XIV → V7000 → Pure Storage
- Executed Active Directory upgrades across three major versions (2003 → 2008 → 2016)
- Administered and maintained virtual machines across VMware clusters
- Managed Windows Server patching, hardening, and lifecycle across the enterprise
- Configured and maintained Cisco UCS blade infrastructure and fabric interconnects
- Monitored system performance, capacity planning, and resource optimization
- Designed and tested disaster recovery procedures and failover processes
- Provided Tier 3 escalation support for complex infrastructure incidents
- Worked with application teams to design and deploy hosting environments for new systems
- Created technical documentation for infrastructure standards and procedures
- VMware
- Exchange
- Pure Storage
- Cisco UCS
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Lead Systems Engineer at Insurance Corporation
On-siteSummary:
- Led virtualization initiative and data center infrastructure buildout. Complete physical-to-virtual migration.
Responsibilities:
- Implemented and managed VMware infrastructure (4.0 → 5.1)
- Data center hardware: Cisco UCS and EMC VNX
- Complete P2V migration of physical environment
- ESX Clusters, HA, DRS, Distributed Switches design
- Network security: Cisco ASA, site-to-site VPN, AnyConnect
- Administered and maintained 600+ virtual machines across VMware clusters
- Managed Windows Server patching, hardening, and lifecycle across the enterprise
- Configured and maintained Cisco UCS blade infrastructure and fabric interconnects
- Monitored system performance, capacity planning, and resource optimization
- Managed the full network stack end-to-end — firewalls, routers, switches, and storage fabric
- Managed enterprise backup operations using Veeam
- Designed and tested disaster recovery procedures and failover processes
- Built secondary data center for regional redundancy
- Provided Tier 3 escalation support for complex infrastructure incidents
- Worked with application teams to design and deploy hosting environments for new systems
- Created technical documentation for infrastructure standards and procedures
- VMware
- Cisco
- EMC
- Veeam
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Network Analyst at Networking Firm
On-siteSummary:
- Delivered full-stack infrastructure solutions for managed services clients — network, virtualization, and messaging implementations across multiple customer environments.
Responsibilities:
- Delivered end-to-end network, virtualization, and Exchange implementations for MSP clients
- Designed and configured Cisco ASA firewalls, routing, and switching for client environments
- Architected Site-to-Site IPsec VPN tunnels connecting distributed office locations
- Deployed remote access solutions using VMware View, Citrix, and Cisco AnyConnect VPN
- Managed multiple concurrent client engagements from design through production handoff
- Cisco
- VMware
- Exchange
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Network & Systems Administrator at Defense Contractor
On-siteSummary:
- Sole IT engineer for a defense contractor building military training simulation systems. Owned the entire infrastructure stack from the ground up — servers, networking, messaging, security, and field deployments.
Responsibilities:
- Orchestrated full infrastructure rebuild from legacy Windows NT to Windows 2003 Active Directory
- Orchestrated network architecture redesign with VLAN segmentation for defense security compliance
- Orchestrated secure 3G remote access deployment for military trainers in isolated field locations
- Executed Exchange migration from 5.5 to Exchange 2000
- Managed end-to-end TCP/IP network infrastructure — design, deployment, and maintenance
- Managed all infrastructure operations, troubleshooting, and vendor relationships as sole IT engineer
- Managed hardware procurement, rack-and-stack, and data center operations
- Implemented Windows Remote Installation Services replacing manual Norton Ghost imaging
- Maintained security compliance and access controls for defense-classified environments
- Windows Server
- Cisco
- Exchange
- Active Directory
Education
Daytona State College
Bachelor of Sciences — Information Technology
Certificates
Microsoft Azure AI Fundamentals
Microsoft
Skills
- PowerShell
- Windows Server
- VMware
- Hyper-V / SCVMM
- Azure
- Cisco
- Docker
- Linux
- Python
- Node.js
- Prometheus
- Grafana
- Cloudflare
- Git
- GitHub
- Terraform
- AI / LLMs
- Omnissa Horizon