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Guillaume O.GO

Guillaume O.

Transitional CIO / CIO – IT Transformation

€2,000/day
Paris, FR
15+ years

Average response time: 1 hour

Freelancer profile translated to English.
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About Guillaume

Transitional CIO and IT transformation consulting, Data/AI and cybersecurity.

I work with general management, CIOs, and executive committees when digital becomes a critical issue: IT departments to restructure, IT governance to clarify, struggling programs, illegible project portfolios, Data/AI trajectories to frame, or cybersecurity to be managed at the right level.

My experience in management positions within large, complex organizations allows me to act at both strategic and operational levels: understanding business challenges, making decisions, structuring, managing teams, and ensuring execution.

My goal: to bring clarity, decision-making, and momentum back into complex digital transformations.
  • French

    Native or bilingual

  • English

    Fluent

Can work on-site
Paris (up to 20km)

Experience

  • Ville de Paris
    Chief Information and Digital Officer
    June 2025 - Today (1 year)
    Member of the executive committee and executive bodies, direct contribution to strategic decisions and resource allocation for a top-tier organization.

    Management and restructuring of an IT department of 1,000 employees: overhaul of governance, re-internalization of key skills, and creation of a Data & AI sub-department to accelerate the industrialization of data/AI uses, generating 10% optimization of the payroll and sustainable improvement of operational performance.

    Management of an annual budget of €150 million and deployment of a digital sovereignty policy generating €8 million in savings, reducing technological dependence and operating costs, with a trajectory of €12 million in 2026.

    Executive sponsorship of structuring transformations: renewal of the financial IT system (€40 million, 3 entities, 3,500 users), modernization of core business systems delivered on time and within budget, deployment of a unified mobile application for over 2 million users.

    Infrastructure rationalization: optimization of a fleet of 8,000 servers, measurable improvement in service quality.

    Strengthening cyber resilience: creation of shared vulnerability indicators and deployment of an internal AI and cybersecurity e-academy to foster acculturation, adoption, and mastery of AI uses.

    Definition and deployment of a responsible data and AI strategy, including the creation of a dedicated Data & AI Lab for rapid prototyping of use cases, to accelerate the assessment of their business value, secure their scaling, and integrate AI into a governance and operational impact trajectory.

    Management of social dialogue on digital transformations and ensuring the continuity of essential services for over 200,000 users.

    Implementation of a responsible and sustainable digital strategy.
    Digital Transformation IT Governance Data & AI Strategy Cybersecurity
  • Conseil Départemental de Seine Saint Denis
    Director of Digital Innovation and IT Systems
    March 2023 - June 2025 (2 years and 3 months)
    Management and restructuring of an IT department of over 200 employees in a context of profound organizational transformation.

    Management of an annual budget of €40 million and a very large-scale IT system: 15,000 workstations, 800 business applications, 2,000 servers, and 3 data centers.

    Rationalization of the application portfolio and optimization of AMS contracts, generating over €4 million in recurring savings.

    Technological foundation transformation: migration to Microsoft 365 for several thousand users and modernization of core business systems.

    Management of the consolidation of 3,000 employees on a single site and associated digital transformation (workstations, networks, and collaborative tools).

    Consolidation and security of critical infrastructures: rationalization of server environments and implementation of two redundant server rooms ensuring business continuity.

    Structured IT, data, and AI governance: implementation of decision-making committees, performance indicators, and enhanced project and investment management.

    Definition and deployment of a Data & AI strategy: governance of uses, deployment of business use cases, organization-wide acculturation program, and structuring of a sovereign data foundation.
  • Skema Business School
    Group Organization and Information Systems Director
    January 2022 - March 2023 (1 year and 2 months)
    Member of the group's executive committee, direct contribution to strategic decisions in a highly competitive international academic environment.

    Management of an IT organization of 130 employees and oversight of a global information system serving 15,000 students and 1,000 employees across 11 international campuses (Europe, Americas, Asia).

    Management of an annual budget of €24 million and allocation of €50 million in multi-year digital investments as part of the group's digital transformation.

    Management of a major academic and administrative IT transformation program: migration of the group's LMS (€15 million program) and modernization of core business systems, strengthening the group's management capacity and performance internationally.

    Modernization of the technological foundation and transformation of infrastructures supporting over 50,000 users internationally.

    Structuring of group IT governance, deployment of a data & analytics strategy, and management of multidisciplinary international teams.

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Education

  • Executive MBA (Master of Business Administration)
    ESCP EUROPE
    2019
    Executive MBA (Master of Business Administration)
  • Executive Education Digital Transformation and Innovation Strategy in the Age of Digital Disruption
    INSEAD
    2019
    Executive Education Digital Transformation and Innovation Strategy in the Age of Digital Disruption

Skill set

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