Senior Firewall Engineer (TS/SCI) — Enterprise Security Architect

D2 Technical Services; Springfield (VA); On-site; USD 130,000 - 140,000; Full time

Benefits offered by this job

Health/Dental/Vision

401(k) match

PTO

STD/LTD/Life Insurance

Referral Bonuses

Professional development reimbursement

Job summary

D2 Consulting seeks a Senior Firewall Engineer to join a high-impact team protecting mission-critical infrastructure. The role requires active TS/SCI clearance and the ability to pass a U.S. Government Polygraph, with DoD 8140/8570 compliance.

You will design secure networks, manage security stacks, and lead incident response for enterprise-scale environments. You will work alongside government and corporate leadership, shaping security operations, and evaluating emerging technologies to stay

Qualifications

• 5+ years in Network Security within large-scale enterprise or global environments.
• BA/BS degree preferred — but strong hands-on experience can substitute for a degree.
• DoD 8140.01 / 8570.01-M IAT Level II compliant certification.
• CSSP Infrastructure Support certification — or drive to earn it within 120 days of starting.

Responsibilities

• Design & build state-of-the-art secure network architectures from concept to implementation.
• Protect the network by managing WAN, LAN, CAN, and remote security environments and handling incidents with speed and precision.
• Own the security stack — firewalls, F5 load balancers, web/mail gateways, IDS platforms, and management tools.
• Lead incident response — investigate, document, and drive corrective action when it matters most.
• Shape security operations by developing SOPs that the broader team will rely on.
• Stay ahead of threats by researching and evaluating emerging network security technologies.
• Be the expert in the room — liaise with contract leadership, customers, and government DAA stakeholders.

Skills

Network security

Incident response

Routers & switches (Juniper, Cisco)

Education

BA/BS degree preferred

Job description

D2 Consulting seeks a Senior Firewall Engineer to join a high-impact team protecting mission-critical infrastructure. The role requires active TS/SCI clearance and the ability to pass a U.S. Government Polygraph, with DoD 8140/8570 compliance.

You will design secure networks, manage security stacks, and lead incident response for enterprise-scale environments. You will work alongside government and corporate leadership, shaping security operations, and evaluating emerging technologies to stay