Senior Network Engineer

ON.energy is building the backbone of energy and AI infrastructure powering grid-safe data centers and mission-critical facilities. The company supplies and operates hyperscale power systems that solve the toughest resilience challenges, delivering custom solutions for AI data centers, mission-critical facilities, and front-of-the-meter assets. ON recently announced a 5GW partnership, with 3GW currently under construction across multiple hyperscale data center campuses. With patented technology and proprietary software, ON.energy develops projects worldwide that set new benchmarks for resilience. ON.energy is seeking a Senior Network Engineer to design, secure, and maintain network infrastructure of Operational Technology (OT) environments. This role requires deep expertise across network topologies, troubleshooting, and security, with a strong preference for hands-on experience securing industrial control networks using Palo Alto firewalls and Moxa switches. KEY RESPONSIBILITIES Design, implement, and maintain OT network architectures, including LAN/WAN, wireless, and industrial network segments. Configure, manage, and troubleshoot Palo Alto next-generation firewalls to enforce network security policy and segmentation between OT zones. Deploy and maintain Moxa industrial switches and other ruggedized networking hardware in OT environments. Diagnose and resolve complex network issues across routing, switching, and security layers, minimizing downtime in production and industrial settings. Design and maintain VLAN structures, subnetting schemes, and IP addressing plans across OT networks. Configure and manage NAT, VPN tunnels, and site-to-site/remote access connectivity. Implement and maintain High Availability (HA) network designs to ensure resilience of critical infrastructure. Apply network security best practices, including segmentation, access control, monitoring, and hardening of OT networks. Collaborate with controls, automation, and cybersecurity teams to support integration of PLCs, SCADA systems, and industrial PCs onto the network. Document network designs, standard operating procedures, and change management records. REQUIRED QUALIFICATIONS Expert-level knowledge of network topologies and structured troubleshooting methodology. Strong hands-on proficiency with TCP/IP, VLANs, routing, switching, subnetting, and NAT. Demonstrated experience designing and supporting site-to-site and remote access VPNs. Solid understanding of network security principles and High Availability design. Experience working within Operational Technology (OT) environments and an understanding of IT/OT network segmentation. Bachelor's degree in a related field, or equivalent professional experience. PREFERRED QUALIFICATIONS Hands-on expertise with Palo Alto firewalls (policy configuration, App-ID, segmentation, VPN, and monitoring). Experience deploying and managing Moxa industrial switches. Familiarity with Siemens PLCs and industrial control system architectures. Experience with SEL (Schweitzer Engineering Laboratories) protective relay and communication devices. Experience networking and supporting Industrial PCs in production/OT environments. Familiarity with Ignition SCADA platform and its network/architecture requirements. Proficiency administering both Windows and Linux environments. Relevant certifications such as PCNSE, CCNA/CCNP, or similar are a plus. CORE TECHNICAL SKILLS Category Skills Networking Fundamentals TCP/IP, VLANs, Routing, Switching, Subnetting, NAT Security Palo Alto Firewalls, VPNs, Network Security, High Availability OT Hardware Moxa Switches, Siemens PLCs, SEL Devices, Industrial PCs Software/Platforms Ignition SCADA, Windows, Linux ON.energy is an equal opportunity employer. This job description is intended to convey information essential to understanding the scope of the role and is not exhaustive of all responsibilities, skills, or qualifications required. For US-based roles - What you’ll get: Competitive salary…