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
Solid 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 prospect in a critical infrastructure domain

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

📌 Security Architect – Ot / Network / Pki Sydney
🏢 New World Management
📍 Sydney