IT System Architect

Job description Randstad Digital are seeking a seasoned, hands-on Senior IT Technical Lead to drive a separation delivery for core IT Foundation tracks within a high-profile business carve-out programme. The assignment starts asap and lasts until June 2027. with a possible prolongation. This assignment spans three critical areas: Identity & Collaboration, Network & Infrastructure, and Service Desk / Site & Facility IT. The guiding objective is to ensure business continuity, avoid unnecessary transformation or redesign, and deliver pragmatic, robust technical solutions to hit critical separation milestones. Please note: This is a hands-on technical ownership and delivery role, not a coordination or PM layer. You will be expected to dive deep into architectures, solve complex problems with engineering teams and vendors, and take definitive technical ownership. Responsibilities Technical Ownership: Own unresolved, cross-domain technical challenges through to resolution alongside internal engineers, service owners, and third-party suppliers. Roadmaps & Solution Design: Translate high-level separation requirements into actionable roadmaps and technical designs across identity, collaboration, infrastructure, and site services. M365 & Identity Architecture: Lead and challenge solution designs regarding Microsoft 365, tenant-to-tenant migration, coexistence, and identity separation. Pragmatic Scope Control: Determine exactly what must change at each milestone versus what can be safely retained or deferred. Cutover & Contingency: Design, validate, and sign off on technical readiness for migrations, cutovers, fallback plans, and service continuity. Risk & Long-Lead Execution: Proactively trigger long-lead technical actions early and escalate material architecture, security, or dependency risks to programme leadership. Qualifications Technical Capabilities Carve-Out / Separation Expertise: Proven, hands-on experience delivering complex IT separations, corporate carve-outs, or large-scale M&A divestment programmes. Microsoft 365 Architecture: Deep, verifiable expertise across Exchange Online, Teams, SharePoint Online, and OneDrive. Identity & Security: Extensive experience with Microsoft Entra ID (Azure AD), on-premises Active Directory, authentication protocols, access controls, and Microsoft compliance/security toolsets. Tenant Migration & Coexistence: Documented track record executing M365 tenant-to-tenant separations, cross-tenant migrations, and multi-tenant coexistence architectures. Core Infrastructure: Broad working knowledge of enterprise networking, hybrid hosting, enterprise ITSM/Service Desk transitions, and multi-site IT cutovers. Personal Qualities Hands-on Technical Authority: Commands respect from engineers, architects, and external vendors through deep technical competence rather than organizational hierarchy. Outcome-Oriented & Accountable: Proactive problem solver who dives straight into technica…