Headcount: 24 (+140%)
Specialism: UK sovereign cloud
HQ: Southampton
This provider of sovereign managed services grew average monthly headcount from 10 to 24 between its fiscal 2022 and 2025, accounts show.
It was founded in 2012 by Stuart McKean, a former British Army Lynx helicopter pilot.
The Nutanix, Trellix and Pulsant partner recently evolved its portfolio from a defence-only focus to also encompass national security and critical national infrastructure (see Q&A below).
View the wider Fast-Growth 50 here.
Q&A with Nine23 CEO Steve Jewell
How have you been able to increase headcount in a flat market?
We have grown headcount through a combination of strategic restructuring and targeted investment in areas where demand is increasing. Over the past year we reviewed our advisory and strategic functions to ensure resources were aligned with areas delivering the greatest near-term operational impact. This allowed us to redirect investment into engineering, security architecture, and service delivery roles that directly support customer outcomes.
At the same time, the evolution of our portfolio from a defence-only focus to three defined sectors (defence, national security, and critical national infrastructure) has opened adjacent market opportunities. These sectors increasingly require specialist capabilities in areas such as secure mobility, sovereign cloud, and high-assurance service delivery. As a result, we have been able to scale technical capability and grow headcount organically despite broader market stagnation.
What mega trend do you think will most shape the year for your company?
The most consequential trend shaping 2026 is the widening disconnect between the UK’s growing demand for sovereign, high-assurance infrastructure and a global technology ecosystem that is rapidly optimising for AI-centric hyperscale workloads.
While AI is the dominant force influencing the technology landscape, the challenge for organisations operating in secure and regulated environments is less about adopting AI itself and more about the industry-wide shift in infrastructure priorities.
Hardware vendors are increasingly focusing production on GPU-driven and AI-tuned architectures, which is beginning to constrain the availability of the specialist non-AI infrastructure required to deliver secure, sovereign IT platforms. At the same time, renewed emphasis on sovereign cloud requirements in the UK is becoming harder to meet, as much of the modern hardware and software ecosystem is now designed primarily for hyperscale cloud environments.
Navigating this tension between rising sovereign demand and a shrinking pool of sovereign-capable infrastructure will be a defining focus for Nine23 in 2026, increasing the strategic importance of providers that can engineer, integrate, and operate sovereign platforms end-to-end for sectors such as defence, national security, and critical national infrastructure.
What’s a fact or quirk about your company most people won’t know about?
Nine23 was one of only two SMEs invited to join the Secure by Design working group with TechUK and DSIT, contributing directly to the development of the national Secure by Design framework. We are also active contributors within the Cyber Security and Resilience (CSR) working groups, helping to shape UK policy for the protection and resilience of critical national digital services.
Does the rise of AI and automation make it less likely you’ll continue to add headcount at the same rate in the coming years?
No. AI and automation enhance the speed, resilience, and scalability of our engineering and service delivery functions, but they are not a substitute for the deep expertise our teams bring. For Nine23, automation is an enabler that allows us to scale operations without compromising the high-assurance standards required in sovereign and regulated environments.
Building and operating these platforms still depends on specialist engineers, architects, testers, and security practitioners. As the technology landscape becomes more complex, the demand for these skills is increasing rather than decreasing, meaning automation will support our teams—not replace them—as we continue to grow.
Name one thing you have planned for the next 12 months
We are preparing to launch a new suite of UK Sovereign services, specifically engineered for high-assurance and regulated environments. Developed through strategic partnerships, these services incorporate modern architecture patterns, strengthened identity and access controls, and enhanced interoperability across regulated sectors, significantly expanding our sovereign and secure-by-design service portfolio.
