IT Network Engineer

About Castelion

Castelion is moving incredibly fast to develop and deliver advanced defense systems at a time when execution matters more than ever. We believe focus and technical excellence are decisive advantages – and we are building a team that can deliver real capability, not just concepts.

This is a rare opportunity to join at an early stage, where your work will directly shape critical systems, influence major technical decisions, and have immediate, real-world impact. 

IT Network Engineer

We are seeking a highly skilled Network Engineer at our Rio Rancho, NM s to implement, manage, and maintain network infrastructures supporting our mission-critical systems. The ideal candidate will bring deep technical knowledge of networking protocols and architecture, an understanding of cybersecurity requirements (e.g., DISA STIGs, hardening, zero trust), and proven experience operating in a fast paced, growing organization. This role will align well with a candidate experienced working in a manufacturing campus setting. An independent, autonomous self-starter personality is a must.

Key Responsibilities:

• Design, deploy, and maintain secure and scalable enterprise network infrastructures, including LAN, WAN, VPN, VoIP, and wireless.
• Collaborate with network team lead, management, cybersecurity, and systems administration teams teams to enable and secure the corporate, OT, guest, and other networks
• Maintain modern hybrid cloud network infrastructure, including workloads on-premises, in major cloud providers, and in the field.
• Configure and manage routers, switches, firewalls, and other network devices from common major vendors.
• Implement and maintain system hardening in compliance with DoD STIGs, NIST frameworks, CMMC, and more.
• Perform troubleshooting and root cause analysis of complex network issues in a multitude of environments.
• Develop and maintain network documentation, diagrams, and standard operating procedures.
• Participate in audits, accreditation, and certification processes.
• Support deployments and field operations, including as-needed travel (5-10%) to other Castelion sites.

Basic Qualifications:

• Bachelor's degree in Computer Science, Information Technology, or a related field (or equivalent experience).
• 3+ years of experience in network engineering roles, preferably in fast-paced companies, startup, defense, or government environments.
• Strong knowledge of networking protocols (TCP/IP, BGP, OSPF, EIGRP, MPLS).
• Hands-on experience with hardware: firewalls, switches, wireless access points, and power.
• Experience applying controls as directed by cybersecurity frameworks (RMF, STIGs, NIST, CMMC).
• Strong documentation and communication skills.
• Strong experience with SD-WAN and software-defined networking (SDN).

Preferred Qualifications:

• Industry certifications such as CompTIA Security+, CISSP, or CCNA.
• Experience with 802.1x and RADIUS for wired and wireless networks.
• Experience supporting classified networks.
• Experience with automation tools (Ansible, Terraform, Puppet, PowerShell DSC).
• Understanding of Zero Trust architecture and secure enclave designs.
• Active Security Clearance

Working Conditions:

• On-site work location: Rio Rancho, NM. 5-10% travel to CA, TX, DC; some after-hours/on-call support may be necessary.
• Occasional lifting of IT equipment (up to 40 lbs) and data center work.

Other Duties

Please note this job description is not designed to cover or contain a comprehensive listing of activities, duties or responsibilities that are required of the employee for this job. Duties, responsibilities and activities may change at any time with or without notice.

Benefits and Perks

All full-time employees are granted meaningful long-term equity, sharing in the company's significant growth trajectory. We offer four (4) weeks of paid time off, ten (10) company-paid holidays, and comprehensive health benefits - including 100% employee-covered medical and strong dependent coverage, along with dental and vision plans. We also provide paid parental leave to support growing families, a $100 monthly fitness stipend to promote health and performance, and onsite EV charging for convenience. In addition, employees enjoy perks like catered meals, company-covered food during high-demand periods, and a fully stocked kitchen to stay fueled throughout the day.

Affirmative Action/EEO Statement

Employment with Castelion is governed on the basis of competence and qualifications and will not be influenced in any manner by race, color, religion, gender, national origin/ethnicity, veteran status, disability status, age, sexual orientation, gender identity, marital status, mental or physical disability or any other legally protected status.

ITAR Requirements

To conform to U.S. Government export regulations, applicant must be a (i) U.S. citizen or national, (ii) U.S. lawful, permanent resident (aka green card holder), (iii) Refugee under 8 U.S.C. § 1157, or (iv) Asylee under 8 U.S.C. § 1158, or be eligible to obtain the required authorizations from the U.S. Department of State.