Network Engineer – Operational Technology (OT)

Job Summary

We are seeking an experienced Network Engineer to design, implement, maintain, and secure network infrastructure supporting an Operational Technology (OT) / industrial environment.

The role will primarily focus on managing a segmented and air-gapped network environment, ensuring reliable and secure communication between industrial systems, servers, network devices, and supporting infrastructure. The successful candidate will also be responsible for firewall management, site-to-site VPN connectivity, DMZ services, Microsoft Entra ID (Azure AD), and network security.

This role requires a strong understanding of both network infrastructure and cybersecurity principles, with particular emphasis on maintaining the availability, integrity, and security of OT environments.

Key Responsibilities

Network Infrastructure & OT Environment

• Configure, maintain, and troubleshoot network infrastructure within an air-gapped OT environment.
• Manage network switches, routers, firewalls, VLANs, routing, and network segmentation.
• Implement and maintain secure network segmentation between OT, IT, DMZ, and other network zones.
• Maintain accurate network diagrams, IP addressing schemes, configuration documentation, and network inventories.
• Perform network configuration changes while minimizing disruption to critical operational systems.
• Configure and troubleshoot site-to-site VPN connections between approved locations or network environments.
• Manage and maintain a DMZ environment hosting web-based services used by clients to upload files.
• Support network and authentication requirements associated with Microsoft Entra ID (formerly Azure Active Directory).
• Assist with identity-related network access, authentication, and connectivity issues.

Industrial Devices & OT Support

• Provide network support for industrial equipment, including industrial printers and other OT-connected devices.
• Troubleshoot communication issues between industrial devices, servers, and network infrastructure.
• Work with OT engineers, vendors, and equipment manufacturers to resolve network-related issues.
• Ensure industrial devices are appropriately segmented and protected from unauthorized network access.
• Understand the operational constraints of industrial environments, including the importance of availability and controlled change management.
• Setting up / troubleshoot SFTP connection.

Network Security & Compliance

• Apply cybersecurity best practices to OT and network infrastructure.
• Maintain strict access controls within the air-gapped environment.
• Identify and mitigate network security risks and vulnerabilities.
• Participate in security assessments, audits, and incident investigations where required; such as ISO 27001
• Maintain network security documentation and configuration baselines.
• Follow formal change management, backup, and disaster recovery procedures.
• Ensure changes to OT networks are properly assessed, tested, documented, and approved before implementation.

Requirements

Technical Skills

• 3+ years of experience in network engineering, preferably within industrial, manufacturing, critical infrastructure, or OT environments.
• Strong understanding of TCP/IP, VLANs, subnetting, routing, DNS, DHCP, and network troubleshooting.
• Hands-on experience with enterprise firewalls.
• Experience configuring and troubleshooting site-to-site VPNs.
• Experience with network segmentation and DMZ architecture.
• Working knowledge of Microsoft Entra ID / Azure AD.
• Experience supporting Windows-based servers and network-connected devices.
• Familiarity with network monitoring and diagnostic tools.
• Understanding of cybersecurity principles and secure network design.

OT / Industrial Experience

Experience working in an Operational Technology (OT), industrial, manufacturing, or air-gapped environment will be highly advantageous.

Candidates should understand the differences between traditional IT and OT environments, particularly:

• Availability and operational continuity are critical.
• Network changes must be carefully controlled and tested.
• Legacy systems and industrial equipment may have strict compatibility requirements.
• Security controls must be implemented without disrupting industrial operations.
• Network segmentation and controlled access are essential to protecting OT systems.

Key Competencies

• Strong analytical and troubleshooting skills.
• Good understanding of network security.
• Ability to work independently in a controlled and security-sensitive environment.
• Strong documentation and communication skills.
• Ability to work with OT engineers, vendors, and external clients.
• Strong attention to detail.
• Good understanding of change management and risk assessment.
• Ability to respond effectively to network incidents and service disruptions.
• Willingness to work outside normal business hours for planned maintenance or critical incidents when required.