Infrastructure security architect

Mission Overview: Keystone Solutions is seeking an Infrastructure, Security and Architecture allrounder for a consultancy mission with our client, guiding the migration of IT from a Belgian entity to the French headquarters.

Key Responsibilities
Assessment & migration strategy
• Audit the Belgian IT landscape: infrastructure, applications, identities, licences, contracts, data flows and technical debt.
• Map Belgian systems against French headquarters standards and identify gaps, overlaps and dependencies.
• Define the target architecture and migration approach for each domain (rehost, replatform, consolidate, retire).
• Build the migration roadmap with phases, milestones, cutover windows and rollback plans.
• Prepare the business case, including costs, risks, licence consolidation and expected savings. Infrastructure & cloud
• Plan and run the migration of servers, storage, virtualization and backup to the headquarters' datacenter or cloud platforms.
• Lead network integration: WAN/SD-WAN interconnection, VPN, DNS, IP addressing, firewalls and site connectivity.
• Run identity consolidation: Active Directory/Entra ID merger and Microsoft 365 tenant-to-tenant migration (mail, Teams, SharePoint, OneDrive).
• Migrate endpoints and device management (Intune/SCCM, MDM) to headquarters tooling with minimal user disruption.
• Make sure monitoring, backup, disaster recovery and business continuity remain covered throughout the transition. Security & compliance
• Align the Belgian entity with the group's security policies, ISO 27001 controls and security tooling (EDR, SIEM/SOC, IAM, PAM, MFA).
• Run risk assessments before and after each migration wave, and keep the risk register up to date.
• Keep GDPR compliance in place during data transfers, and update records of processing, DPAs and retention rules.
• Handle NIS2 obligations in both jurisdictions, coordinating with the Belgian CCB and the French ANSSI frameworks where relevant.
• Secure the transition period: temporary trust relationships, privileged access, data-in-transit protection and decommissioning of legacy access.
• Make sure Belgian legacy systems are securely wiped and decommissioned, with evidence kept for audit. Architecture & governance
• Act as design authority for all technical decisions in the integration programme.
• Document as-is and to-be architectures, standards and integration patterns.
• Rationalize the application portfolio and define the future of Belgium-specific tools (HR, payroll, invoicing, local regulatory systems).
• Make sure Belgian legal and operational requirements are preserved in the target solution, such as social secretariat interfaces, local tax and e-invoicing, and language needs (FR/NL). Stakeholders & vendors
• Act as the main technical link between Belgian management, French headquarters IT, and external partners.
• Manage vendors, integrators and MSPs: contract transitions, termination notices, TSAs and handover of services.
• Report progress, risks and decisions to steering committees.
• Support change management with user communication, training, hypercare after cutover, and service desk alignment. Knowledge transfer & handover
• Make sure local IT knowledge is documented and transferred to headquarters teams.
• Define the post-migration support model and operational runbooks.
• Hand over to run teams once each workstream is stable, and close the programme with a lessons-learned review. Required Qualifications and

Skills:
• French and English mandatory.
• Able to speak with all stakeholders from teams to C level.
• Comfortable operating under Keystone Solutions' consultancy model, embedded on site or in hybrid mode with the client across Belgian and French entities. Consultancy Nature of Work:
• Operate as a Keystone Solutions consultant embedded with the client, coordinating efforts across application, infrastructure and security domains to ensure a smooth migration.
• Work on site with client teams when required, collaborating closely with Belgian and French stakeholders to align timelines, risks and change plans. Dynamic Projects Across Clients:
• Engage in a flagship migration program while building experience that translates to future client engagements, from infrastructure modernization to application lifecycle optimization.
• Leverage exposure to diverse environments, tools and governance models, strengthening your adaptability and problem solving capabilities. Turbo-Charged Learning and Development:
• Benefit from Keystone Solutions' coaching culture, peer communities and targeted trainings around networking, application platforms, security, automation and architecture practices.
• Access hands-on knowledge sharing across consultants to accelerate mastery of containerization, SDLC governance and network delivery topics including F5. Ambition Skyrocketing within a Consultancy Framework:
• Grow your career through varied client engagements that expand your leadership footprint, from technical coordination to stakeholder management at C level.
• Earn recognition by delivering measurable outcomes in complex cross country transformations, building a track record that unlocks senior consultancy paths. Keystone Solutions Values in a Consultancy Context:
• Client centricity, craftsmanship, integrity and teamwork guide every mission. Being a K-Stone means you bring these values to each client project, consistently aligning decisions with impact and trust.
• We champion clarity and accountability, ensuring every engagement is delivered with transparent communication and quality execution. Role-Specific Consultant Advantages:
• Apply your infrastructure, security and architecture expertise across multiple client scenarios, from data center and network transitions to application platform readiness and SDLC maturity.
• Strengthen bilingual leadership by facilitating workshops, steering committees and operational ceremonies in both French and English.

How to Apply
If you are ready to tackle technical and strategic challenges in a dynamic consultancy environment, apply today at Keystone Solutions Career Portal.