Senior IT & Network Engineer - Cross-Domain Security

Quartermaster AI Inc; New York (NY); Hybrid; USD 140,000 - 210,000; Full time

Benefits offered by this job

Hybrid work model

Medical, dental, and vision benefits

Career growth in defense-tech

Job summary

Quartermaster AI Inc. is seeking an IT Engineer to support IT operations, endpoint management, and cross-domain networking across sensitive environments. The role combines hands-on troubleshooting with secure network design and maintenance, ensuring data integrity across classified enclaves.

The candidate will work across IT and security, deploying LAN/WAN infrastructure, enforcing policy, and mentoring junior staff while supporting air-gapped networks and cross-domain data transfer. U.S.

Qualifications

• 6-9 years in IT engineering, systems administration, and/or network engineering, including senior-level (L2/L3) support and hands-on network build-out.
• Strong networking expertise: routing and switching, VLANs, firewalls, VPNs, wireless, and protocols such as TCP/IP, DNS, DHCP, BGP, OSPF, and QoS.
• Hands-on experience installing and configuring enterprise network hardware and troubleshooting complex issues.
• Experience administering endpoints and identity across macOS, Windows, and Linux, including MDM and identity providers (e.g., Google Workspace, JumpCloud).
• Experience standing up and supporting secure or classified networks, including air-gapped or multi-enclave environments.
• Familiarity with cross-domain data transfer and security controls.
• Working knowledge of DISA STIGs, RMF/ATO.
• Proficiency scripting and automating with Python, Bash, or PowerShell, with strong documentation habits.
• Excellent troubleshooting and communication skills.
• Must be a U.S. citizen.

Responsibilities

• Provide comprehensive technical assistance for all levels of issues—from daily help desk tickets to complex, senior-level escalations—collaborating with the IT team to maintain support across hardware, software, operating systems, and connectivity for macOS, Windows, and Linux.
• Manage the endpoint fleet and identity - device provisioning, MDM, and access control through identity providers (e.g., Google Workspace, JumpCloud).
• Own onboarding and offboarding, ensuring timely and secure provisioning and deprovisioning of accounts, devices, and access.
• Administer and support SaaS and collaboration platforms, and maintain accurate IT asset inventory and documentation, including runbooks, SOPs, and diagrams.
• Implement and enforce IT security policies - device management, encryption standards, and acceptable use - in partnership with the security team.
• Improve internal IT processes, tooling, and automation, and mentor junior IT staff.
• Design, deploy, and maintain LAN/WAN, wireless, and VPN infrastructure across multiple sites, ensuring highly available network operations.
• Install, configure, and support network hardware - routers, layer 2/3 switches, next-generation firewalls, and access points - using protocols such as VLAN, VRF, OSPF/BGP, QoS, and DNS.
• Build and maintain classified and air-gapped networks (e.g., NIPR/SIPR/JWICS-style enclaves), including multi-enclave and zero-trust architectures.
• Set up and operate cross-domain solutions (CDS) to move data securely between low-side and high-side networks, preserving data integrity and required security controls.
• Configure and manage COMSEC and Type-1 / HAIPE in-line network encryptors and associated key material in accordance with policy.
• Harden network infrastructure to DISA STIGs and support RMF/ATO activities, audits, and documentation (topology, IP allocation, cabling, and configurations).
• Monitor, troubleshoot, and optimize network performance; manage firmware and scheduled upgrades; and provide on-call support for critical infrastructure.

Skills

Networking expertise

Endpoint management

IT security practices

Automation scripting

Documentation

Education

Bachelor's degree in IT/CS

Equivalent hands-on experience

Tools

Google Workspace

JumpCloud

MDM

Palo Alto Networks

Job description

Quartermaster AI Inc. is seeking an IT Engineer to support IT operations, endpoint management, and cross-domain networking across sensitive environments. The role combines hands-on troubleshooting with secure network design and maintenance, ensuring data integrity across classified enclaves.

The candidate will work across IT and security, deploying LAN/WAN infrastructure, enforcing policy, and mentoring junior staff while supporting air-gapped networks and cross-domain data transfer. U.S.