Security Architect – OT / Network / PKI

Security Architect – OT / Network / PKI

Energy Sector | Critical Infrastructure | Hybrid (Australia)

The Role

A major critical infrastructure organisation is seeking a Security Architect to lead the design and implementation of security across complex Operational Technology (OT) environments.

This is a hands-on architecture role, responsible for securing live environments across network, identity, and PKI domains — not a governance-only position.

You'll play a key role in a large-scale cyber uplift program, shaping how security is implemented across OT systems that underpin essential services.

Key Responsibilities

• Design and deliver end-to-end OT security architecture
• Develop High-Level and Low-Level Designs (HLD/LLD) across key platforms
• Lead network segmentation and firewall architecture (IEC 62443 aligned)
• Own PKI architecture (CA hierarchy, HSM integration, certificate lifecycle)
• Implement and govern NAC solutions (Cisco ISE / Aruba ClearPass)
• Translate AESCSF, SOCI Act, IEC 62443 into enforceable technical controls
• Contribute to OT SIEM and detection capability (e.g. Microsoft Sentinel)
• Provide technical leadership and risk input to senior stakeholders

About You

Essential Experience

• 8+ years in cyber security / network security architecture
• Strong experience in OT / ICS or critical infrastructure environments
• Proven delivery of complex architecture artefacts (HLD, LLD, threat models)
• Deep expertise in:
• Network segmentation & firewall design
• PKI architecture and certificate lifecycle management
• NAC implementation (802.1X, profiling, policy enforcement)
• Experience with OT protocols (e.g. SCADA, DNP3, IEC 61850, Modbus)

Regulatory Experience

• Exposure to Australian frameworks such as:
• AESCSF
• SOCI Act
• Essential Eight

Desirable

• Microsoft Sentinel / Defender for IoT
• Azure (ExpressRoute, Arc, Private Endpoints)
• HSM technologies (e.g. Thales)
• Energy sector experience
• The ability to successfully obtain baseline security clearance

Why Apply

• Work on systems of national significance
• Join a major cyber uplift program with real investment
• High-impact role with visibility across executive and regulatory stakeholders
• Exposure to real-world OT environments (substations, control systems)
• Long-term opportunity in a critical infrastructure domain

If you have what we are looking for and are looking for your next engagement, APPLY NOW.