Systems Administrator with Enterprise Ops Experience

CHRISTOPHER R. CROSSEN

St. Charles, MO 314-***-**** ️ ***********@*****.***

CAREER SUMMARY

To contribute to a forward-thinking IT organization where I can apply my expertise in enterprise server management, virtualization, and automation. Skilled in Microsoft Active Directory, VMware vSphere, and PowerShell scripting, I aim to support and optimize large-scale infrastructure environments while continuing to grow my technical and leadership capabilities.

KEY SKILLS

IT Infrastructure: Active Directory, Group Policy, DNS, DHCP, DFS, Certificate Services

Automation & Scripting: PowerShell, VBScript, WMI, ADSI, Jenkins

Virtualization: VMWare vSphere 8.x, ESXi 8.x, Omnissa Horizon VDI

Systems Management: Windows Server (2003-2022), SCCM, RDS

Enterprise Tools: Entra ID (Azure AD Sync), EMC SAN/NAS, Failover Clustering

Other: Disaster Recovery, Systems Deployment, Performance Optimization

EXPERIENCE

2012-Present RGA Reinsurance Group of America Chesterfield, MO

Senior Systems Engineer

Deployment, maintenance, and monitoring of Windows Server systems

Administer and maintain Microsoft Active Directory

Configured and supported OnPrem AD to EntraID sync server

Automation of processes and tasks using Microsoft PowerShell, Jenkins, and RDS

Maintain & administer Active Directory Group Policy, DNS, & DHCP scopes

Administration of DFS Namespaces and replication

Maintained and deployed updates and packages via Microsoft SCCM

Maintained and managed Omnissa Horizon VDI environment

Act as escalation point for multiple teams in the environment

2006-2012 First Bank Hazelwood, MO

Senior Systems Engineer

Install, configure, and deploy new Windows 2003 and 2008 servers on IBM server hardware

Written and deployed numerous PowerShell and vbscripts using WMI and ADSI

Maintain & administer Active Directory Group Policy, DNS, & DHCP scopes

Deploy and maintain Microsoft Failover Clusters

Administer and manage Microsoft Enterprise Certificate Authority

SAN and NAS administration using various EMC hardware and software products

Designed, deployed and maintain DFS Replication groups for archival of branch server data

Developed and use failover utility for bi-annual Disaster Recovery exercise

Deploy and maintain ESXi 4.x hosts and guests

Support and troubleshooting of Citrix published applications and desktops

1998-2006 BJC Health Care St. Louis, MO

Senior Analyst - Information Systems

Install, configure, and deploy new Windows 2000 and 2003 servers on IBM server hardware

Support and build upon BJC’s current implementation of Microsoft Identity Integration Server

Maintained Windows Patch Management solution with Enterprise Configuration Manager

Written and deployed numerous vbscripts using WMI and ADSI

Managed printers using HP WebJet Admin

Create and support Published Applications in Citrix Presentation server 3.x and 4

Deployed and configured radius support on Raritan IP-Reach units for IP based KVM solution

Create, manage, and maintain print servers and queues

Maintain backups and restores via Tivoli Storage Manager on Windows servers

1998-1998 A Technological Advantage St. Louis, MO

Microsoft Certified Trainer

1996–1998 Wave Technologies St. Louis, MO

Support Technician

1995–1996 Metrix Computers St. Louis, MO

Computer Technician

1993–1995 PC House Inc. St. Louis, MO

Computer Technician

CERTIFICATIONS

Microsoft Certified Systems Engineer (MCSE 4.0)

Microsoft Certified Professional plus Internet (MCP+I)

Microsoft Certified Professional (Windows XP)

Microsoft Certified Trainer (MCT) (expired)

Certified NetWare Administrator (CNA) NetWare 4.1

A+ Certified Computer Technician

EDUCATION

Highschool: GED

Additional Schooling: Various Computer related Extended Education courses

INTERESTS

PC Hardware, Programming, Commercial Art., Game Design, Pinball

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