Senior Network Security Engineer

SimSpace serves as an AI Proving Ground where organizations can confidently train, test, and outmaneuver adversaries in any environment. Trusted by allied governments, militaries, enterprises, and research institutions worldwide, SimSpace enables adaptive, AI-ready defenses that stay ahead of evolving threats. Founded in 2015 by experts from U.S. Cyber Command and MIT Lincoln Laboratory, the platform unifies training, testing, and validation in a realistic, live-fire simulation—helping teams evaluate security investments, optimize performance, and compress cyber readiness cycles from months to days.

Why join SimSpace? We are an organization that is focused on building our culture and mindfully enhancing our atmosphere every day which is why we have collaborated on an integral value system. Our governing philosophy of being Human Centered is deeply embedded within our value system. We apply this philosophy to every one of our internal team members, external clients, and their customers.

How Do We Work? We believe that people are at the center of everything we do. SimSpace fosters a culture of continuous learning, curiosity, and professional growth. That belief shows up in action: in-house training, internal and external learning platforms, cyber conferences, industry events, and dedicated time for skill development. Our people are empowered to shape their careers - and it shows. Year over year, SimSpace consistently outperforms industry benchmarks in internal mobility, promotions, and total rewards growth.

Who Thrives Here? We are a team of innovators, protectors, and problem-solvers. We believe diversity of thought and experience fuels better solutions, and we’re committed to building teams that reflect the communities we serve. Whether you’re remote or office-based, you’ll collaborate with talented colleagues across departments and time zones, united by the mission to create a safer digital world.

We invite you to apply today!

The Senior Network Security Engineer position is a senior technology practitioner responsible for the collaborative design, implementation, monitoring, maintenance, and security of enterprise network infrastructure and security platforms across SimSpace corporate offices and data centers across the United States and Europe.

This individual will serve as a senior technical resource and subject matter expert for both network and security infrastructure, helping lead operational support, architecture, modernization, and incident response efforts. The role combines traditional network engineering responsibilities with expanded ownership of network security operations, secure access technologies, firewall management, web application protection, and vulnerability management.

The successful candidate will possess deep technical expertise in enterprise networking and security technologies, strong analytical and troubleshooting skills, and the ability to lead initiatives and mentor junior engineers. Effective collaboration with infrastructure, cloud, security, and business stakeholders is critical to success in this role.

What You Will Do (Responsibilities)

• Act as the subject matter expert for SimSpace network and network security infrastructure

• Design, implement, support, and secure enterprise network infrastructure and software-defined networking solutions

• Configure and maintain complex VMware environments leveraging NSX-T, DVS, and software-defined networking technologies

• Contribute to the design and implementation of resilient, secure, and scalable network architectures

• Configure and troubleshoot virtual networking, VLANs, VRFs, traffic forwarding, and hybrid cloud connectivity

• Troubleshoot all levels of network connectivity issues including, but not limited to, network outages, switch failures, network performance, network interface card (NIC), cabling, TCP/IP configuration, etc.

• Manage and optimize secure web access technologies including content filtering, secure web proxy, SSL inspection, DLP, and zero-trust remote access platforms

• Administer next-generation firewall infrastructure, including firewall policies, ACLs, NAT, IPS/IDS, VPNs, routing, segmentation, and high-availability configurations

• Manage web application firewall (WAF) and edge security technologies, including rulesets, custom protections, bot mitigation, and application-layer threat prevention

• Perform troubleshooting of complex network and security incidents, including outages, performance issues, routing failures, VPN issues, and security events

• Assist in vulnerability management activities for network and security infrastructure, including performing web application vulnerability assessments using DAST tools, coordinating remediation efforts, and validating corrective actions

• Monitor network and security infrastructure performance and execute corrective actions as needed

• Support centralized logging, security monitoring, alerting, and threat analysis activities across network and security platforms

• Assess existing network and security technologies to identify opportunities for modernization, improved security posture, and operational efficiency

• Maintain documentation, standards, and operational procedures for network and security infrastructure

• Provide technical leadership, mentorship, and guidance to junior engineers and operational staff

• Participate in maintenance activities, infrastructure upgrades, and business-driven technology projects

What You Will Bring (Requirements and Bonus Skills)

• 8+ years of network engineering experience

• 5+ years of hands-on network security or security infrastructure experience

• Strong understanding of enterprise networking concepts, protocols, and infrastructure design

• Strong knowledge of routing, switching, TCP/IP, DNS, VPNs, network segmentation, and secure remote access technologies

• Experience managing next-generation firewalls, secure web gateways, WAFs, and zero-trust security platforms

• Strong hands-on experience with firewall policy management, NAT, IPS/IDS, VPN technologies, and routing protocols including BGP

• Strong understanding of web certificates, PKI, TLS/SSL encryption, certificate lifecycle management, and troubleshooting certificate-related connectivity or inspection issues

• Experience with LAN/WAN design including IP allocations, segmentation, VLAN implementation, and hybrid cloud networking

• Proficiency with packet captures, traffic analysis, and network troubleshooting methodologies

• Experience with centralized logging, SIEM, security monitoring, alerting, and log analysis platforms to support threat detection and incident investigation

• Familiarity with vulnerability management and security assessment tools

• Experience with monitoring and observability platforms

• Ability to lead technical implementations, infrastructure upgrades, and operational initiatives

• Ability to quickly learn and adapt to new technologies and platforms

• Strong written and verbal communication skills

Preferred Qualifications

• Industry certifications such as CISSP, CCNP Security, GIAC, or equivalent

• Experience supporting cloud networking and cloud security platforms

• Experience supporting compliance frameworks such as SOC 2, ISO 27001, or CMMC

• Understanding of how to leverage AI and automation technologies to improve security operations, operational efficiency, threat analysis, and workflow optimization

We’re proud to offer a competitive and comprehensive package designed to support your well-being, growth, and success:

• Compensation. Base salary range: $135,000 - $205,000 reflecting our confidence in your expertise and impact, with the opportunity for bonuses tied to company performance and individual contributions.

• Health & Wellness. Comprehensive medical, dental, and vision benefits, plus savings plans—coverage starts on day one!

• Mental Health Support. Access to company-paid counseling, coaching, and resources for you and your family through Spring Health.

• Financial Well-Being. Plan for your future with a 401(k)-retirement savings plan featuring a company match.

• Flexible Time Off. Take the time you need with unlimited vacation and dedicated health & wellness days. SimSpace provides flexible solutions to meet the diverse work-life needs of team members.

• Parental Leave. Paid leave plans to support you and your loved ones during life’s most important moments.

• Ownership Opportunities. Equity stock options at hire, with annual performance-based grants—become an invested stakeholder in our shared success.

• Referral Rewards. Earn $1,500–$3,500 for every qualified hire through our employee referral program.

• Peloton Interactive Wellness Program. Full- and partial- subsidized membership plans and equipment discounts to help you reach your personalized fitness goals.

• Continuous Learning. Access a LinkedIn Learning membership to prioritize your personal and professional development.

• Social Connections. Monthly reimbursements for meaningful connections with teammates through our SocialSpace Community.

• Extra Perks. Legal plan coverage, pet insurance, wellness reimbursements, and more to simplify life’s details.

Join SimSpace and enjoy benefits that enhance your career, health, and happiness!

SimSpace is an Equal Opportunity Employer:

In compliance with federal law, all persons hired will be required to verify identity and eligibility to work in the United States and to complete the required employment eligibility verification document form upon hire.

SimSpace is an Equal Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, age, pregnancy, genetic information, disability, status as a protected veteran, or any other protected category under applicable federal, state, and local laws. We are committed to providing an inclusive and welcoming environment for all members of our staff, clients, volunteers, subcontractors, vendors, and clients.

Research shows that women and people from underrepresented groups only apply to jobs if they meet all of the qualifications. However, no one ever meets 100% of the qualifications. SimSpace encourages you to break that statistic and to apply. We look forward to your application!

We also consider qualified applicants regardless of criminal histories, in accordance with applicable law. We are committed to providing reasonable accommodations for qualified individuals with disabilities in our job application procedures. If you need assistance or accommodation due to a disability, please contact careers@simspace.com.

SimSpace does not accept unsolicited resumes from employment agencies.

Actual compensation for the position is based on a variety of factors, including, but not limited to affordability, skills, qualifications and experience, and may vary from the range.