Security Engineer (ICS / OT Security & Architecture) (REF: SDA/SE)

ATAL Data Centre Infrastructure Limited; Hong Kong; On-site; HKD 480,000 - 720,000; Full time

Job summary

ATAL Data Centre Infrastructure Limited in Hong Kong seeks a Security Engineer focused on OT/ICS security and architecture. You will lead risk assessments, audits, and architectural hardening for wastewater control systems, bridging IT and OT to protect critical infrastructure against cyber threats.

You will implement DMZs, industrial firewalls, and data diodes, ensure ISO 27001 alignment, and coordinate third-party security testing and regulatory compliance with HK OG CIO guidelines.

Qualifications

• Bachelor's degree in Information Security, Computer Science, Computer/Electronic Engineering, Automation/Control Engineering, or related technical discipline.
• Minimum 3–5 years in information security with track record in ISO 27001 ISMS implementation/auditing and OT/ICS/SCADA security.
• Deep understanding of ISO 27001 framework and mapping IT controls to OT environments.
• Familiarity with Purdue Model, DMZ setup, and industrial network segmentation.
• Experience preparing for ISO 27001 certification audits and writing SRAA reports.

Responsibilities

• SRAA & Compliance: Conduct comprehensive Security Risk Assessment and Audit (SRAA) on hardware (PLCs, HMIs, switches) and software (SCADA platforms, databases) against ISO 27001, IEC 62443.
• Network Segmentation (DMZ): Design and implement DMZs, industrial firewalls, and data diodes to isolate Wastewater Production Control Zone from other zones.
• Endpoint & Host Security: Deploy antivirus, IDS/IPS, patch management, and vulnerability hardening on servers, NAS, and VMs.
• OGCIO Compliance Management: Ensure adherence to HK OGCIO guidelines including S17, G3, G54, and G51.
• Security Auditing & Penetration Testing: Liaise with third-party firms for audits and pre-handover testing; remediate findings.
• Data Integrity & Logging: Establish audit trails, access controls, and logging to protect CIA of time-series and ML databases.

Skills

OT/ICS Security

Security Engineering

Governance & Compliance

ISO 27001

Threat & Vulnerability Management

Education

Bachelor's degree in Information Security or related

Tools

DMZ design

Job description

Security Engineer (ICS / OT Security & Architecture) (REF: SDA/SE)

We are seeking a skilled and passionate Security Engineer specializing in Operational Technology (OT) and Industrial Control Systems (ICS). In this role, you will lead the security risk assessments, audits (SRAA), and architectural hardening (such as DMZ implementation) for our wastewater treatment control systems (SCADA/PLC). You will bridge the gap between IT and OT to safeguard our critical infrastructure against cyber threats and ensure regulatory compliance.

Responsibilities:

SRAA & Compliance: Conduct comprehensive Security Risk Assessment and Audit (SRAA) on both hardware (PLCs, HMIs, network switches) and software (SCADA platforms, databases) levels against international standards (e.g., ISO 27001, IEC 62443).

Network Segmentation (DMZ): Design, review, and implement robust network segmentation architectures, specifically setting up Demilitarized Zones (DMZ), industrial firewalls, and data diodes to isolate the Wastewater Production Control Zone (DCS) from the Management Information Zone and DMZ.

Endpoint & Host Security: Deploy and manage antivirus software, Intrusion Detection/Prevention Systems (IDS/IPS), patch management, and vulnerability hardening across physical servers, NAS devices, and Virtual Machines (VMs).

OGCIO Compliance Management: Ensure the entire system infrastructure adheres strictly to Hong Kong OGCIO guidelines, including S17 (Baseline IT Security Policy), G3 (IT Security Guidelines), G54 (Incident Handling), and G51 (Security Risk Assessment & Audit).

Security Auditing & Penetration Testing: Act as the primary technical liaison for independent, certified cybersecurity firms to conduct comprehensive third-party security audits and pre-handover penetration testing. Document and remediate all identified vulnerabilities.

Data Integrity & Logging: Establish and monitor comprehensive audit trails, access controls, and logging functions to guarantee the Confidentiality, Integrity, and Availability (CIA triad) of time-series and ML result databases.

Requirements:

Bachelor’s degree from an accredited university in Information Security, Computer Science, Computer/Electronic Engineering, Automation/Control Engineering, or a related technical discipline.

Strong background in security engineering, governance, risk, and compliance.

Minimum of 3–5 years in information security, with a proven track record in both ISO 27001 ISMS implementation/auditing and OT/ICS/SCADA security.

Deep understanding of ISO 27001 framework and how to map its IT controls into an operational technology (OT) environment.

Familiarity with the Purdue Model, DMZ setup, and industrial network segmentation.

Proven experience in preparing for internal/external ISO 27001 certification audits and writing SRAA reports.

Self-motivated with a positive can-do attitude

Established in 1977, ATAL Engineering Group (“ATAL”) is a leading electrical and mechanical (“E&M”) engineering service provider headquartered in Hong Kong, with operations in Macau, Mainland China, US and UK. Serving a wide spectrum of customers from different sectors, ATAL provides multi-disciplinary and comprehensive E&M engineering and technology services in four major segments, including Building Services, Environmental Engineering, Information, Communications and Building Technologies (“ICBT”) and Lifts & Escalators.

We invite talents who aspire to open a new and challenging career page and are passionate in developing career further. For more information, please visit our website.