OT Security Engineer

Location: Dublin, Ireland
Employment Type: Full-Time
Salary: €75,000 – €90,000

A technical team expanding its operational technology footprint is adding a Security Engineer who thrives inside the guts of OT networks and production systems—not just observing from the perimeter. The work is heavily engineering-focused, with hands-on design, implementation, and troubleshooting across controllers, machinery, and security controls. This is a role for someone who wants to influence how the environment matures while delivering practical security outcomes.

The Role

• Build, tune, and validate security controls across OT networks and production platforms.

• Design and refine segmentation boundaries, zoning layouts, and routing patterns.

• Engineer and maintain firewall rule sets, ACL structures, and traffic pathways between operational layers.

• Lead equipment onboarding—interface mapping, communication validation, and control-plane behaviour checks.

• Build and maintain baseline configurations for switches, controllers, edge devices, and monitoring points.

• Analyse system behaviour, cross-talk, and unexpected signalling patterns during change windows.

• Implement and validate security controls with minimal performance impact on production systems.

• Perform engineering-focused incident triage: packet inspection, log correlation, device state review, rollback reasoning.

• Contribute to internal architecture reviews and maintain technical design notes, diagrams, and configuration references.

• Work with external partners to align environments, validate remediation plans, and verify technical changes.

• Strengthen observability—logging routes, telemetry capture, and health-state indicators for OT assets.

Skills & Experience

• 5+ years in OT network engineering, ICS/SCADA systems, or industrial networking environments.

• Strong understanding of segmentation, VLAN layouts, protocol behaviour, and controller communication paths.

• Experience configuring and maintaining firewalls and L2/L3 network equipment in production.

• Familiarity with frameworks such as NIST 800-82 or IEC 62443 applied in operational engineering scenarios.

• Ability to interpret traffic flows, protocol anomalies, and equipment state transitions.

• Hands-on experience with packet analysers, vulnerability scanners, endpoint controls, and configuration management tools.

• Comfortable operating in controlled, regulated, or compliance-bound industrial environments.

• Clear, structured documentation habits—baseline diagrams, change notes, configuration references.

• Experience performing technical root-cause investigations and contributing to OT security improvement plans.

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