Senior IT-/OT Network & Security Administrator (m/w/d), Ref. 1380

About This Opportunity

We are representing a confidential engineering and consulting organization serving telecommunications, media, transport, and public sector clients. Our talent team is seeking a Senior IT/OT Network & Security Administrator to join their multidisciplinary team in Cologne.

This role focuses on securing and optimizing industrial infrastructure environments, bridging traditional IT systems with operational technology in production-critical settings. You'll work across the full lifecycle from architecture design through implementation and operations support.

Responsibilities

• Administer, design, and evolve IT and OT infrastructure in industrial environments
• Implement and manage firewalls from various vendors including Cisco, Fortinet, Sophos, Stormshield, and Hirschmann
• Administer and optimize IT/OT networks using Cisco, Hirschmann, LANCOM, Huawei, and related components
• Design and implement OT network architectures with segmentation following the Purdue Model
• Plan, build, and administer OT-DMZ infrastructures
• Deploy and manage network and host monitoring solutions such as CheckMK, Security Onion, Trisul, HiVision, and WhatsUp Gold
• Administer and secure Active Directory environments across IT and OT domains
• Manage Windows and Linux systems plus database environments (MS SQL, MySQL)
• Secure and administer SCADA, MES, and PDMS systems including GE Fanuc Proficy iFIX and Siemens PCS7
• Plan and execute industrial cyber security measures
• Conduct security assessments, risk analyses, and hardening measures following established standards and best practices
• Implement CIS Hardening Guidelines in IT/OT environments
• Develop and introduce cyber security processes including incident response, risk management, and technical design authority
• Design and implement IT/OT interfaces and security concepts
• Support integration of SIEM, asset discovery, and monitoring solutions
• Guide system and infrastructure updates plus migrations in production-critical environments
• Provide technical consulting to customers and project teams on OT security and industrial networking
• Create and maintain technical documentation, policies, and test procedures

What We're Looking For

Required Qualifications:

• Completed degree or training in IT, network technology, automation technology, electrical engineering, or comparable qualification
• Several years of professional experience administering and designing IT/OT infrastructures
• Strong knowledge of network and firewall technologies
• Experience in industrial cyber security / OT security
• Excellent skills administering Windows and Linux systems
• Experience with Active Directory and network/host monitoring
• Knowledge of industrial systems and protocols, plus experience with SCADA, MES, and process control systems
• Experience in network segmentation and securing industrial environments
• Knowledge of the Purdue Enterprise Reference Architecture Model
• Experience with security frameworks, hardening guidelines, and risk/incident management
• German language proficiency for client interaction

Preferred Certifications:

• GICSP – Global Industrial Cyber Security Professional
• GCIH – GIAC Certified Incident Handler
• GPEN – GIAC Penetration Tester
• GXPN – GIAC Exploit Researcher & Advanced Penetration Tester
• GCFA – GIAC Certified Forensic Analyst
• GCDA – GIAC Certified Detection Analyst

Technical Environment:

• Network: Cisco, Hirschmann, LANCOM, D-Link, Huawei
• Firewalls: Cisco, Fortinet, Sophos, Stormshield, Hirschmann
• Monitoring: CheckMK, Security Onion, Trisul, HiVision, WhatsUp Gold
• Security: CIS Hardening, SIEM, Asset Discovery, Incident Response, Risk Management
• Operating Systems: Windows Server, Windows 10/11, Linux (CentOS, Ubuntu, Debian, RHEL)
• Directory Services: Windows Active Directory
• Databases: MS SQL, MySQL
• OT/SCADA: Siemens PCS7, GE Fanuc Proficy iFIX, ACRON MES/PDMS

How We Work With You

Candidates apply through Get A Job.ai, where our recruiting team will conduct an initial screening. We will then submit qualified candidates to our client for consideration. Please do not contact the client directly, as all communication is managed through our process to ensure confidentiality and proper representation.

Our client offers diverse project work with strong technology focus, individual development opportunities including specialized training and certifications, flat hierarchies with a collaborative atmosphere, hybrid working with flexible hours, permanent contract with 30 vacation days plus additional time off, profit sharing, corporate benefits platform, and quarterly company events.

Pay

Compensation details will be discussed during the screening process based on experience and qualifications.

Equal Opportunity: Get A Job.ai is committed to creating a diverse and inclusive recruitment process. We welcome applications from all qualified candidates regardless of race, color, religion, gender, national origin, age, disability, or veteran status.