Senior IT System Architect

Senior IT System Architect - 3 Months - Brussels Belgium

At RELYzIT, we don't recruit — we build.

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About the Role

RELYzIT Talent is seeking a Senior IT System Architect for a high-impact, freelance assignment with our client in Brussels. This is a 3-month project where your expertise will directly shape the security, performance, and resilience of critical network and cloud infrastructures. You’ll be joining a community of elite builders, empowered to deliver outcomes that matter.

Why This Role Matters

Our client is navigating complex digital transformation and industrial modernization. As a Senior IT System Architect, you will be instrumental in designing, optimizing, and securing hybrid environments that underpin essential business operations. Your work will ensure robust connectivity, seamless cloud integration, and industrial-grade security — enabling innovation and operational excellence at scale.

What You’ll Be Doing

• Architecting and optimizing secure, scalable network infrastructures using Fortinet and Cisco technologies.


• Designing and implementing cloud solutions that align with business and operational requirements.


• Driving the integration of IT and OT (Operational Technology) environments, ensuring seamless and secure data flows across industrial systems.


• Monitoring and analyzing network performance using SolarWinds, proactively identifying and resolving bottlenecks or vulnerabilities.


• Implementing and managing advanced security solutions, including Zscaler, to protect critical assets and data.


• Collaborating with cross-functional teams to translate business needs into technical solutions that deliver measurable impact.


• Providing technical leadership and mentorship to internal teams, fostering a culture of continuous improvement and innovation.


• Documenting architectures, processes, and best practices to ensure knowledge transfer and operational continuity.

What We’re Looking For

• Proven ownership mindset: you take initiative, drive outcomes, and thrive in environments where your expertise shapes the solution.


• Advanced problem-solving skills, with a track record of delivering impactful results in complex, multi-stakeholder settings.


• Strong communication and collaboration abilities, able to bridge technical and business perspectives.


• Builder-first attitude: you see challenges as opportunities to create, improve, and elevate the status quo.


• Experience working in agile, fast-paced environments, ideally within industrial or mission-critical sectors.

Technical Skills & Experience

• Fortinet & Cisco: Advanced expertise (5–8 years) in designing, deploying, and managing enterprise network solutions.


• Cloud Technologies: Deep experience architecting and integrating cloud platforms (public, private, or hybrid).


• Industrial (OT) Environments: Advanced (5–8 years) experience with industrial systems, protocols, and security.


• Network Performance Monitoring: Senior-level (8–10 years) hands-on experience with SolarWinds or equivalent tools.


• Zscaler: Strong competence in deploying and managing Zscaler security solutions.

Language Proficiency

• Fluency in English is required.


• Professional proficiency in Dutch and/or French is a significant asset.


• Additional language skills are highly valued.

Other Requirements

• Availability for a 3-month freelance engagement in Brussels, Belgium.


• Eligible to work in Belgium (no relocation or visa sponsorship provided).


• Experience in Agile/Scrum environments is a plus.


• VECTOR7™ Signal Stack vetting: All candidates will be evaluated through RELYzIT’s proprietary, multi-signal assessment process, ensuring only the most capable builders join our community.

This is a freelance position for a 3-month project in Brussels, Belgium. RELYzIT Talent is committed to placing elite tech talent in roles that drive innovation and real-world impact.