Umer Mahmood

Infrastructure & Security Engineer · most recently Site Lead / Technical Manager (Senior Systems Administrator)

Greater Seattle, WA · Available now · Greater Seattle or remote · umerm89@gmail.com · linkedin.com/in/umer-mahmood-225293163

Security clearance: Previously held a U.S. government security clearance; eligible for reinstatement. Details available to employers on request.

Summary

Infrastructure and security engineer with more than 10 years of government contracting experience on classified networks, secure datacenter operations, and cloud infrastructure. Site Lead for a 12-administrator datacenter team; contributed to dozens of successful Authorization to Operate (ATO) efforts and led two complete packages. Hands-on with RMF/STIG compliance, Nutanix and VMware virtualization, AWS, and automation, and now building security tooling of my own.

  • Dozens of ATO efforts across DoD programs, including two complete packages led end to end at SMX and the secure campus wireless ATO delivered with NSA integrators.
  • Led a 12-administrator datacenter team as Site Lead and Product Owner; migrated 100+ VMs from VMware to Nutanix HCI with under four hours of downtime.
  • Cut costs where security allowed it: $100K+ per year through microsegmentation, and an AWS Outpost bill from $1,400 to $300 a month.

Experience

Founder

YATC LLC (Yet Another Tech Company) · Remote · Dec 2023 – Present
  • Founded a managed service provider delivering secure infrastructure and compliance services
  • Design, operate and harden a self-hosted platform on a Rocky Linux VPS: GitLab CE with CI runners, OpenBao secrets with AppRole delivery, an nginx edge proxy with automated TLS renewal, Tailscale-only administration, and containers run read-only, non-root, with all capabilities dropped
  • Build security tooling with written requirements, decision logs and automated tests: netstig (network STIG evidence), Spotter (a macOS terminal with bounded AI assistance), the STIG Checklist Editor, and an OpenBao desktop client

Site Lead / Technical Manager (Senior Systems Administrator)

SMX · Ridgecrest, CA · Oct 2023 – May 2025
  • Led two complete ATO packages from control selection through authorization
  • Led a 12-administrator datacenter team and drove PI planning as Product Owner, aligning technical work with operational priorities
  • Migrated 100+ VMs from VMware to Nutanix HCI with less than four hours of downtime
  • Engineered microsegmentation that reduced annual costs by $100K+ while meeting infrastructure security requirements
  • Defined platform ownership and service expectations through a PaaS Shared Responsibility Model and service catalog
  • Deployed AWS Outpost and used CloudWatch to cut its monthly cost from $1,400 to $300
  • Implemented STIG hardening and remediated Nessus findings to support secure operations and authorization requirements

Senior Systems Administrator

Life Cycle Engineering · Ridgecrest, CA · Sep 2022 – Oct 2023
  • Primary technical point of contact for three ATO efforts
  • Administered Rubrik protection for 50 TB of data, sustaining a 99% backup success rate
  • Deployed SolarWinds NPM monitoring across 1,000 network devices
  • Hardened 200+ servers and 1,000+ network devices against DoD STIG requirements

System Administrator

Trowbridge & Trowbridge · Ridgecrest, CA · Oct 2018 – Sep 2022
  • Delivered the secure campus wireless ATO in collaboration with NSA integrators
  • Developed a DoD secure Wi-Fi solution supporting classified SIPRNet operations
  • Migrated ~150 VMs from VMware VxRail to Nutanix HCI
  • Reduced critical vulnerabilities by approximately 80% through Tenable ACAS management across approximately 100 assets

Network Administrator

Epsilon, Inc. · Ridgecrest, CA · Nov 2016 – Oct 2018
  • Managed full-lifecycle network infrastructure across multi-vendor environments
  • Completed hardware and software upgrades with minimal downtime; led the first on-time hardware refresh in 18 months

Information Technology Specialist

IntellecTechs, Inc. · Bridgeport, CA · Apr 2016 – Nov 2016
  • Replaced hardware, performed backup restorations, and resolved ~50 Remedy service desk tickets weekly on a cleared site

Network Administrator / Engineer

Kurtis Company · San Francisco, CA · Oct 2014 – Apr 2016
  • Conducted A/V and network site surveys, created network diagrams, and supervised installations of routers, switches, wireless APs and IP cameras

Earlier: IT support technician (The Gamer's Network, 2009–2011) and freelance web developer / IT consultant (2009–2010), Modesto, CA.

Independent projects

  • netstig — Python CLI that pulls network device configs, diffs them against baselines, and emits STIG Viewer .ckl checklists for ATO packages.
  • Spotter — Native macOS terminal with an AI assistant whose level you set; secrets stay in the Keychain and every risky command asks first. 1,700+ tests.
  • STIG Checklist Editor — Browser-based STIG checklist editor powered by React and Go WebAssembly, with CKL and CKLB export.
  • Bao GUI — Go and Fyne desktop client for OpenBao: versioned secrets, tokens, transit operations and Keychain-backed profiles.

Platform engineering — Rocky Linux, GitLab CE, OpenBao and hardened containers: application delivery, scoped secrets and documented operations.

Built with AI assistance under written requirements, decision logs and automated tests. How I work with AI.

Skills

Security & Compliance
STIG hardening, RMF, ATO packages, Nessus, Tenable ACAS, eMASS, OpenRMF, SCAP, IDS, Kiwi Syslog, microsegmentation (Nutanix Flow)
Systems & Cloud Platforms
AWS (Outpost, VPC, EC2, S3, Security Groups, CloudWatch, Systems Manager), Nutanix HCI and Prism, VMware vSphere/vCenter/ESXi, Microsoft Hyper-V, Windows Server, Red Hat, Oracle Linux, Ubuntu, CentOS
Networking
Cisco IOS, Aruba (AirWave, ClearPass), Juniper, Brocade (Layer 3, Fibre Channel), F5 BIG-IP, TCP/IP, DHCP, DNS, VPC
Automation & Tooling
PowerShell, Python, Ansible, Tanium, Docker, GitLab CI, Go and Swift for independent projects
Operations
SolarWinds NPM, ServiceNow, Remedy, CloudWatch, Rubrik backup (50 TB+), Active Directory and Group Policy
Leadership
Site Lead for a 12-administrator team, Product Owner for PI planning, Agile delivery, vendor and project coordination, PaaS shared-responsibility model and service catalog

Education

Bachelor of Science, Cloud Computing (AWS track)
Western Governors University (online) · In progress, part-time

Computer Science coursework toward an Associate degree
Modesto Junior College, Modesto, CA · 2007 – 2009

Certifications

  • Nutanix Certified Professional – Multicloud Infrastructure 6 (issued Mar 2025)
  • CompTIA CySA+ ce (valid through Nov 2027)
  • CompTIA Security+ ce (valid through Nov 2027)
  • LPI Linux Essentials (issued Feb 2022)
  • Microsoft Technology Associate: Networking Fundamentals (issued Oct 2016)

Previously held and exam history

  • AWS Certified Cloud Practitioner (held 2023 – Aug 2026, expired; renewal planned)
  • ISC2 CCSP exam passed Oct 2023; certification not held (endorsement window lapsed)

Planned

AWS Certified CloudOps Engineer – Associate and AWS Certified Solutions Architect – Associate; exams planned, not yet scheduled.