Senior Network Security Engineer

Job Type: Contract / Long-Term

Role: Senior Network Security Engineer

Work Environment: Hybrid Enterprise Infrastructure

Location: Mechanicsville, VA 23116

Position Overview

We are seeking an experienced Senior Network Security Engineer to implement, secure, and support enterprise network, cloud, and computing infrastructure. The ideal candidate will have strong hands-on experience with network security, firewalls, Azure networking, SIEM, WAF technologies, SD-WAN, and hybrid infrastructure environments.

This role will be responsible for day-to-day network security operations as well as architecture, design, incident response, vulnerability remediation, threat hunting, documentation, and implementation of security solutions across a large distributed enterprise environment.

Key Responsibilities

• Design, implement, and maintain secure hybrid network architectures across on-premises and Microsoft Azure environments.
• Manage and support Palo Alto firewalls, firewall policies, security rules, and access controls.
• Review firewall rule requests and ensure compliance with established security standards.
• Support Azure networking and ExpressRoute connectivity in a hybrid enterprise environment.
• Implement, manage, and maintain Web Application Firewall (WAF) technologies and validate WAF placement, exposure, and connectivity.
• Monitor and analyze security events using SIEM platforms such as Splunk.
• Lead investigation, containment, and response activities for network security incidents.
• Conduct proactive threat hunting, anomaly detection, and network security monitoring.
• Perform network security assessments and identify opportunities for improving security posture.
• Identify, prioritize, and remediate network security vulnerabilities.
• Support penetration testing activities and coordinate remediation of identified findings.
• Diagnose network and system security issues using logs, monitoring tools, SIEM platforms, diagnostic software, and other test equipment.
• Ensure network security architecture meets operational and security standards before and after implementation.
• Develop and maintain network security standards, architecture documentation, topology diagrams, IP addressing schemes, firewall rules, and access-control documentation.
• Research emerging security technologies, threats, and best practices and recommend appropriate solutions.
• Work closely with Infrastructure, Cloud Engineering, and Information Security teams on enterprise security initiatives.
• Independently manage assigned network security projects from design through implementation and operational support.
• Participate in on-call support for critical security incidents and infrastructure issues.

Required Technical Skills

• Enterprise Network Security
• Palo Alto Firewalls
• Microsoft Azure Networking
• Azure ExpressRoute
• Web Application Firewall (WAF)
• Splunk / SIEM
• SD-WAN
• Firewall policy and rule management
• Network security architecture and design
• Incident response and security investigation
• Threat hunting and anomaly detection
• Vulnerability assessment and remediation
• Penetration testing support
• Network monitoring and troubleshooting
• IP addressing, access controls, and network topology
• Security documentation and architecture diagrams

Ideal Candidate

• Strong experience working in large-scale enterprise network environments.
• Hands-on expertise securing hybrid on-premises and cloud infrastructure.
• Strong understanding of network security architecture, firewall technologies, WAF, SIEM, and cloud networking.
• Ability to independently troubleshoot complex network and security issues.
• Strong analytical, documentation, communication, and problem-solving skills.
• Comfortable collaborating with infrastructure, cloud, and cybersecurity teams while independently managing assigned initiatives.