Senior IT/OT Network Architect: Cutover & DMZ Lead

ZealHire Inc.; United States; Remote; USD 120,000 - 180,000; Full time

Job summary

ZealHire Inc. seeks a senior enterprise network engineer to own the IT/OT network workstream for a two-site carve-out in an M&A transaction.

You will design the L3.5 DMZ and the L3 network, map connectivity, and run the cutover on site with a written rollback plan. The role requires 10+ years of enterprise network experience, CCNP or higher, hands-on routing/switching, DMZ policies, and IT/OT segmentation (Purdue ISA/IEC 62443).

Qualifications

• Must be able to start 11/9/2026.
• 10+ years in enterprise network engineering with lead/design responsibility and recent hands-on config work.
• Experience leading at least one live cutover with a written rollback plan.
• CCIE, GICSP, PCNSE or CCSE.
• DMZ design under a restrictive policy using relays, proxies and per-flow rules.
• Cisco routing and switching at CCNP level or equivalent, VLANs, OSPF and BGP.
• Strong communication.
• US citizens.

Responsibilities

• Lead the network workstream end to end: design it and build it.
• Run the network cutover on site.
• Map connectivity at each site including IT/OT boundary crossings.
• Design the L3.5 DMZ and L3 network changes for cutover.
• Stand up DHCP relay, device AAA and time source for L3.
• Coordinate monitoring sensor points with OT Cybersecurity Engineer.
• Write the network section of the cutover runbook and run tests.
• Support hypercare and keep diagrams, IP plans, and configs updated.

Skills

10+ years in enterprise network eng

IT/OT segmentation

DMZ design

CCNP level routing & switching

OSPF & BGP

TACACS+ / RADIUS / DHCP relay

Lead live cutover

Strong communication

US citizens

Tools

TACACS+ / RADIUS

DHCP relay

NTP

Job description

ZealHire Inc. seeks a senior enterprise network engineer to own the IT/OT network workstream for a two-site carve-out in an M&A transaction.

You will design the L3.5 DMZ and the L3 network, map connectivity, and run the cutover on site with a written rollback plan. The role requires 10+ years of enterprise network experience, CCNP or higher, hands-on routing/switching, DMZ policies, and IT/OT segmentation (Purdue ISA/IEC 62443).