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FOR IMMEDIATE RELEASE
18 August 2025

London, UK

Defence Holdings PLC

("Defence" or "the Company")

Defence Holdings Appoints Former Microsoft Ventures UK CEO as Chief Technology Officer

Defence Holdings PLC (LSE: ALRT), the UK's first listed software-led defence company, is pleased to announce the appointment of Andrew McCartney as Chief Technology Officer ("CTO"), effective immediately. McCartney is a recognised pioneer in AI infrastructure for national security, having co-founded Whitespace, a UK-based deep-technology company delivering generative AI capabilities into defence, public sector, and highly regulated industries. A former CEO of Microsoft Ventures UK, he brings decades of experience building, scaling, and deploying secure, sovereign AI systems in complex, mission-critical environments.

This appointment follows the recently announced long-term strategic partnership between Defence Holdings and Whitespace, where the partnership are co-developing sovereign AI applications for high-priority defence and national security use cases. As CTO, McCartney will lead the design and deployment of our AI product stack aimed at redefining how defence capabilities are conceived, scaled, and delivered across UK and allied domains.

Key Highlights

●    Former CEO of Microsoft Ventures UK, where he launched the company's first global venture innovation platform outside the US, scaling dozens of high-growth technology businesses.

●    Co-Founder of Whitespace, the AI platform powering live UK Ministry of Defence deployments.

●    Proven track record in delivering deployable AI infrastructure, cyber-resilient platforms, and mission-ready software systems for defence and national security applications.

●    Deep strategic network across defence, government, and technology ecosystems in the UK and allied nations, enabling rapid market access and partnership formation.

●    Will lead the design, build, and deployment of Defence Holdings' AI product stack, targeting critical defence priorities and positioning the Company at the forefront of the software-first transformation in global defence.

Strategic Rationale

The global defence sector is undergoing a structural shift from hardware platforms to software-first ecosystems, creating urgent demand for secure, compliant, and resilient AI infrastructure. McCartney's appointment embeds deep technical leadership at the core of Defence Holdings' strategy, directly aligning with the Company's plan to become a leading provider of sovereign digital capabilities.

Having built Whitespace into a trusted supplier of AI infrastructure within live UK defence and national security programmes, McCartney understands the technical, operational, and regulatory complexities required to deploy at the edge. His expertise in scaling trusted platforms across insight-poor, data-rich environments positions him uniquely to architect the next generation of Defence Holdings' capabilities.

McCartney's appointment marks the first in a series of planned senior hires designed to deepen Defence Holdings' technical, operational, and strategic strength as it executes its five-year plan.

Credentials

Andrew McCartney is the Co-Founder of Whitespace, a UK deep-technology company

delivering AI-native infrastructure into defence, national security, and regulated public sector

environments. Since 2015, McCartney has built mission-critical platforms for organisations

operating in complex, data-rich environments where insight, security, and interoperability are

non-negotiable.

Under McCartney's leadership, Whitespace has:

●    Delivered AI platforms now actively supporting frontline Ministry of Defence Operations.

●    Integrated Collective OS, its proprietary AI platform, into live national security networks.

●    Joined the Oracle Defence Ecosystem as a founding member, expanding allied technology collaboration.

●    Been selected for the UK Ministry of Defence's "Engine for Growth" programme, accelerating sovereign innovation into frontline operations.

Prior to founding Whitespace, McCartney served as the inaugural CEO of Microsoft Ventures

UK, launching the company's first global innovation hub outside the United States. Over

three decades, he has built and scaled frontier technology ventures spanning AI, cyber

resilience, and sovereign-grade digital infrastructure.

Leadership Commentary

Andrew McCartney, Chief Technology Officer of Defence Holdings, commented:

"We are at the very beginning of a fundamental shift in how defence capability is conceived, built, and deployed. Over the next decade, the leaders will be those who can deliver sovereign, AI-native infrastructure that works in the harshest real-world conditions. Secure, explainable, and trusted at the edge. At Defence Holdings, we have the means to move faster than traditional players, deliver systems that change the tempo of operations, and define the software-first era of defence. We're not waiting for the future to arrive. We're building it, and this is just the start."

James Norwood, Chairman of Defence Holdings, added:

"Andrew has spent a decade building the capabilities that modern defence actually needs - resilient, deployable, sovereign AI infrastructure. His appointment sends a clear message: Defence Holdings isn't here to observe the future of defence, we're here to build it. This will be the first of several strategic additions we expect to make to our leadership team in the months ahead."

About Defence Holdings PLC (ALRT)

Defence Holdings PLC is a London‑based publicly listed (ALRT) defence technology platform. The Company focuses on developing and acquiring AI-driven analytics, autonomous systems, secure communications, and critical infrastructure solutions across land, sea, air, space, and cyber domains. Supported by deep capital‑markets insight and long-term tech partnerships, the Company is dedicated to transforming European defence capabilities.

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Media Enquiries
Brian Stockbridge, Director
Defence Holdings PLC
Tel: +44 (0)20 3855 5551 · Email: [email protected]