John IliadisPhD · CISSP · CISM · CRISC · C|CISO · COBIT · ITIL · CMgr MCMI

Technology & Cybersecurity Executive

Dr. John Iliadis

Cybersecurity · Digital Transformation · IT Operations

Dr. John Iliadis directs technology infrastructure and cyber operations for mission-critical financial services serving tens of thousands of clients — delivering resilient digital services, informed risk decisions and security strategy aligned with business outcomes across more than 20 years of executive leadership.

Athens, Greece

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Dr. John Iliadis, IT Infrastructure Director and cybersecurity executive in Athens, Greece
20+ years Technology and cybersecurity experience
IT Infrastructure Director TEIRESIAS S.A. · since 2019
PhD · MSc in Information Security University of the Aegean · Royal Holloway College, University of London
CISSP · CISM · CRISC · C|CISO Ten cybersecurity and management credentials

Areas of expertise

Specialisations across cybersecurity and technology leadership

Cybersecurity leadership (CISO)

Technology leadership (CIO)

NIS2 & EU cyber governance

Cyber risk & GRC

Digital transformation

Executive impact

Measurable outcomes across security, resilience and technology

Selected evidence across a career at TEIRESIAS S.A. — mission-critical financial infrastructure serving tens of thousands of clients — and cybersecurity community leadership. Metrics are attributed to the role in which they were achieved.

Cybersecurity & risk current role, 2019–present

  • Designed and established an outsourced Security Operations Centre with custom SOC use cases for internal incident response coordination.
  • Architected a zero-trust security transition across enterprise infrastructure.
  • Introduced design-stage cyber-risk assessment using ISO 27001 Annex A controls.
  • Achieved a 37% increase in service availability while containing OPEX growth under 5% in a documented transformation initiative.
  • Initiated 24/7 IT operations for critical business services.

Infrastructure & resilience prior role, 2012–2019

  • Retained service availability above 99.93%.
  • Improved disaster recovery readiness by 85%.
  • Reduced backup-window duration by 73% with encrypted, deduplicated backup.
  • Zero-downtime migration of core infrastructure for tens of thousands of users.
  • Reduced lateral movement risk and cut IT support costs by 37% through zero-client VDI.

Technology transformation across career

  • Directed cloud transformations and AI governance for a mission-critical financial services organisation.
  • Improved workstation performance by 36% through VDI consolidation.
  • Reduced IT operational costs by 14% and maintenance costs by 28%.
  • Improved energy efficiency by 83% through infrastructure modernisation.
  • Managed EU-wide R&D project budgets up to €5M per project.

Team & community leadership

  • Directs a team of 18 professionals delivering cyber operations and service resilience for tens of thousands of clients.
  • As President of ISC2 Hellenic Chapter (2023–2025): membership +20%, social-media following +24%, event attendance +80%.
  • As Board Member (2021–2023): sponsorships +150%, speaking invitations +50%, social-media following +100%.
  • Multiple national and global cybersecurity leadership awards (2022–2026).

Leadership focus

Connecting secure operations with business priorities

Across more than two decades in technology and information security, the work has combined operational leadership, technical change and the development of people and teams. See the full executive profile and publications.

Cybersecurity strategy & risk

Architecting enterprise security strategies and enabling informed risk choices that support business outcomes. Includes ISO 27001, GDPR, NIS2 and AI governance.

Infrastructure & cyber operations

Leading technology infrastructure, secure architecture and 24/7 cyber operations for mission-critical financial services.

Technology transformation

Cloud migration, zero-trust adoption, AI governance and infrastructure modernisation — delivered with measurable resilience and cost outcomes.

People & business alignment

Developing multidisciplinary teams, mentoring professionals and communicating complex cybersecurity objectives to boards and non-technical stakeholders.

Experience & education

A career across infrastructure, research and leadership

Professional experience

  1. IT Infrastructure Director

    TEIRESIAS S.A. · Athens, Greece

  2. IT Infrastructure Assistant Director

    TEIRESIAS S.A. · Athens, Greece

  3. Network Security Administrator

    TEIRESIAS S.A. · Athens, Greece

  4. R&D Project Coordinator

    Intrasoft International · Athens, Greece

  8. Technical Support

    Self-employed · Small and medium businesses · Athens, Greece

Education & selected credentials

  • Management & Leadership

    Chartered Management Institute · CMgr MCMI

  • Negotiations

    Athens University of Economics and Business

  • Business Administration

    University of the Aegean

  • PhD, Information & Communication Systems Security

    University of the Aegean

  • MSc, Information Security

    Royal Holloway College, University of London

  • BSc, Computer Engineering

    Technological Educational Institute of Athens

Professional credentials include CISSP, CISM, CRISC, C|CISO, ISSMP, CCSP, CCSK, CSSLP, SSCP, CMgr MCMI, COBIT, ITIL, DPO Executive and many more certifications and certificates.

Professional service & recognition

Contributing to the cybersecurity community

2025–present

Chair of the Audit Committee

ISC2 Hellenic Chapter

2025–present

Advisory Board Member

MSc in Law and Information & Communication Technologies, University of Piraeus.

2023–2025

President of the Board of Directors

ISC2 Hellenic Chapter — membership +20%, event attendance +80%, multiple EMEA awards.

2021–2023

Board Member

ISC2 Hellenic Chapter — sponsorships +150%, speaking invitations +50%, social-media following +100%.

Recognition

Awards & distinctions

For speaking engagements, keynotes and conference appearances, see the talks & interviews page. For authored articles and research, see publications. The research archive collects theses and academic papers. The Applied R&D archive collects all past R&D projects I had participated in.