Senior Infrastructure Architect (IT/OT)
Critical Infrastructure
About the role
We design, build and operate the IT and OT infrastructure behind large critical-infrastructure programmes — highways and tunnels, airports, ports, rail, energy transmission and industrial plants.
You will be the lead architect for these environments: enterprise-grade network and cloud on one side, secure integration with operational technology on the other.
This is a broad role — we are not looking for someone who ticks every box. We want a strong architect with deep enterprise-infrastructure and security expertise and a genuine working understanding of OT. The rest we build around you.
What you’ll do
- Design enterprise-grade network and data-centre infrastructure for large projects
- Define hybrid-cloud strategy and lead Azure migrations (landing zones, IaC, platform engineering)
- Build high-availability and disaster-recovery concepts for systems that cannot go down
- Design secure IT/OT segmentation and integration toward SCADA and industrial control systems
- Develop Zero Trust architectures and support SOC/SIEM implementation
- Ensure compliance with NIS2, ISO 27001 and IEC 62443
- Act as technical counterpart to EPC contractors, integrators and client stakeholders
What you need must-have
- 10+ years in large-scale infrastructure projects, with a track record as lead or principal architect
- Deep hands-on networking: BGP, OSPF, VXLAN/EVPN, MPLS, SD-WAN — on Cisco, Juniper, Fortinet or Palo Alto
- Strong Microsoft Azure architecture (networking, firewall, virtual WAN, security)
- Infrastructure security: IAM, PKI, vulnerability management, SIEM/EDR concepts
- A working understanding of OT — you have designed or secured an IT/OT boundary in practice
- Degree in Computer Science, Information Systems or Engineering, or equivalent experience
- Fluent English; German an advantage
- Excellent stakeholder communication across engineers, contractors and clients
What helps nice-to-have
- Sector experience in transport, energy, aviation, ports or heavy industry
- OT protocol knowledge: OPC-UA, Modbus, Profinet, IEC 61850, digital substations
- Virtualisation and storage: VMware, Hyper-V, Nutanix, Veeam, NetApp / Dell EMC / Pure
- Microsoft platform: Windows Server, Active Directory, Entra ID, Intune, Defender
- DevOps tooling: Terraform, Ansible, GitHub/GitLab, Jenkins
- Certifications such as CISSP, Azure Solutions Architect Expert, CCNP/CCIE, ISA/IEC 62443, GICSP — any one or two is a strong signal
- Experience in EPC or PPP delivery models
What’s on offer
- Ownership of the architecture across live infrastructure programmes
- Certification and training budget, including OT/ICS security tracks
- Flexible working, travel arrangements, pension and relocation
How to apply
Send your CV and a line on why this role fits. Meeting most of the must-haves is enough — apply. All approaches are handled confidentially.
Apply — boris@szelcsanyi.net