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EURO2DAY – Sthenos AI: The EFA Group subsidiary betting on “smart defence”

STHENOS AI, founded by EFA GROUP in 2025, develops Artificial Intelligence solutions for the evolution of defence Command and Control (C2) systems into next-generation architectures (C6ISR), filling a gap in the Greek defence ecosystem.

CEO Markos Hatziminas and Chief Technology Officer Georgios Gkekas describe the company’s journey to Euro2day.gr, along with its export strategy and plans for the future.

At a time when Artificial Intelligence is gradually emerging as a key pillar of defence transformation, few may know that there are Greek companies with deep technological backgrounds working to fill critical operational gaps, redefining the way decisions are made in modern defence systems.

One of the most characteristic examples is STHENOS AI, founded by EFA GROUP in 2025 as a specialised company developing advanced Artificial Intelligence solutions for defence and dual-use applications.

The company designs and implements the AI backbone that enables the evolution of existing Command & Control (C2) systems into modern, next-generation architectures, as well as the transition from traditional C2 to integrated C6ISR systems.

In this context, STHENOS AI CEO Markos Hatziminas and the company’s Chief Technology Officer Georgios Gkekas spoke to Euro2day.gr about how the company’s business “journey” began, the broader role of Artificial Intelligence in the development of EFA GROUP’s solutions, and its plans for the future.

As Markos Hatziminas explained, “STHENOS AI is a defence-focused builder of Artificial Intelligence systems within EFA GROUP, and it was created to go far beyond a purely supporting role. It is a company with its own direction, speed and technical depth, designed to develop advanced Artificial Intelligence capabilities while keeping ownership of data, intellectual property and technical direction within the group.”

“Our main objective is the next generation of Command and Control systems, which we are developing side by side with SCYTALYS, also an EFA GROUP company. We develop Artificial Intelligence to support decision-making, not to make decisions in place of people.

The goal is to deliver the real value that Artificial Intelligence was meant to bring, helping the human “in the loop” work faster, with greater clarity and stronger options, while responsibility and final decisions remain exactly where they belong.

At the same time, we support different companies across EFA GROUP, providing Artificial Intelligence solutions for serious, high-impact projects. And when a project grows in size or we reach the limits of our capacity, we scale either by “doubling” the structure of our teams so we can take on more work in parallel, or by bringing in external support to accelerate delivery.

Although our core today is Artificial Intelligence, we see STHENOS as a company that moves together with emerging technologies. In the long term, our vision is to incorporate more technologies as they mature and become relevant to the defence sector. That is why we have already started exploring quantum technology step by step, so that we stay ahead of what is coming,” he added.

What you need to know about Sthenos AI

▶ Founded in 2025 as an independent AI company within EFA GROUP, protecting ownership of data, intellectual property and technical direction within the group.

▶ Develops the AI backbone for the transition from traditional C2 systems to next-generation C6ISR, alongside SCYTALYS (also EFA GROUP).

▶ Already employs 18 people (75% technology team), with a target of 22 in the first wave of growth; further hiring within 2026 is not ruled out.

▶ Announced strategic partnerships with Hewlett-Packard Enterprise (HPE) and Infinitum; new moves “will be made known when they offer clear value to the market”.

▶ Began work on two new products in January 2026; management describes 2026 as a “turning point” for the company.

▶ Researches quantum technology through a specialist working alongside the machine learning team.

How the STHENOS AI business “journey” began

Referring to the first steps of STHENOS AI, Mr Hatziminas said that “the idea of creating a new company within EFA GROUP came from what I experienced personally very early on, when I joined the group as project lead on Artificial Intelligence integration. I was truly passionate about machine learning, and that position gave me a clear picture of an upcoming gap. Not only in what existed then, but also in what would emerge in the years ahead.

I could see how quickly Artificial Intelligence was evolving, especially in the US, where AI in defence had already started to become a key topic, while in Europe it was still mainly a subject of discussion and not many people truly believed in it.

After that realisation, I carried out extensive research with my partner to confirm what the right structure should be. It became clear to us that having a dedicated Artificial Intelligence company within a group like EFA GROUP has significant advantages.

It protects intellectual property and data ownership, raises the “ceiling” of what the group can build in-house, and moves faster because it controls its own technical direction.

It also creates new revenue streams, turning Artificial Intelligence into a real product and capability rather than just a support function. And just as importantly, it helps educate and upgrade the group as a whole, so that data drives thinking and decisions while Artificial Intelligence becomes a shared culture and a long-term strategic advantage.”

The gap in the Greek defence ecosystem

Asked whether there was a gap they identified in the market and wanted to fill, the CEO of STHENOS AI replied that “the gap we identified was not in the global defence market as a whole, but specifically in the Greek defence ecosystem. Then, and even today, there is essentially no other company in Greece apart from SCYTALYS developing Command and Control systems, and there was certainly no Artificial Intelligence company aiming to upgrade and further develop these systems.

At the same time, most major defence investments by Greece were made, and continue to be made, in international companies rather than Greek ones. So the gap we wanted to fill was the loss of a domestic capability, one that strengthens the ecosystem and allows more value, innovation and know-how to remain in Greece.

At the same time, our goal is to bring as many Greek engineers as possible back to Greece, because we constantly see top talent leaving for abroad in search of lower taxation and more opportunities for advancement.”

The STHENOS AI solutions portfolio

For his part, referring to the STHENOS AI solutions portfolio, Mr Gkekas stressed that “beyond our main objective, which is delivering next-generation Command and Control systems, we approach the integration of new technologies into defence systems holistically.

In practice, this means there is a wide thematic range in the defence sector that can benefit from Artificial Intelligence technologies. We are not limited to solutions applied in the field, such as communications between units and operations centres or mission planning and organisation; we also work on solutions for more organisational matters such as unit training and optimisation of the army’s supply chain. And finally, let us not forget the benefits Computer Vision can bring, providing “eyes” where the human factor tires. For this reason, STHENOS AI has created a team dedicated to providing Computer Vision solutions.”

The role of Artificial Intelligence within EFA GROUP

On the broader role of AI in the development of EFA GROUP’s solutions, Mr Hatziminas commented that “for EFA GROUP, Artificial Intelligence is not an isolated feature, but a way to substantially raise the value of our solutions and make them more effective and more operationally useful.

The main role of Artificial Intelligence is to automate, improve existing functions and add new capabilities to products, with an emphasis on supporting decision-making and making better use of information.

In rarer cases, we at STHENOS also develop such operational automations, while more generally there are many Artificial Intelligence tools that support our day-to-day operation and internal activities.

To use a simple metaphor, the EFA GROUP companies deliver the “building”, the core platform, fully functional. We come in to add the “smart technology” inside it: systems that provide a better picture, automation and more speed. Sometimes it is necessary and built in, so that the system meets modern requirements, and sometimes it is an upgrade the customer chooses whether they want.”

Team growth and export strategy

Speaking about the STHENOS AI team, Mr Gkekas revealed that “it already numbers 18 people, and 75% of them belong to the technology team that develops the solutions. These people come mainly from polytechnic schools and natural science faculties and have a long technological background.

This also shows the company’s deep commitment to technology. With this number of people, we now have a capable, critical mass that makes us immediately able to deliver Artificial Intelligence systems.

Most importantly, this has been achieved across all areas of specialisation in the technology team, from machine learning and data science to technology infrastructure design.

The first wave of team growth will be complete once we reach 22 people. As we anticipate very dynamic growth during 2026, we do not rule out a continuation of this trend leading to more hiring, with the parallel creation of more specialisations according to the needs of each project.”

It is worth noting that STHENOS AI recently announced strategic partnerships with Hewlett-Packard Enterprise (HPE) and Infinitum. Asked whether other similar partnerships are in the works, Mr Gkekas replied that “our strategy focuses on creating a strong ecosystem around Artificial Intelligence and modern software. In this context, we are in continuous dialogue with companies that share the same vision and have deep expertise in the field.

We move methodically and with a long-term perspective, announcing partnerships only when they can substantially accelerate the realisation of our vision. Our next moves will be made known when they offer clear value to the market.”

As is well known, EFA GROUP essentially follows an export strategy, with the group being at least 70–80% export-oriented. Asked whether STHENOS AI will follow a similar export policy, Mr Hatziminas stressed that “our company will certainly have an export orientation, because the solutions we develop address an international market and outward orientation is part of the EFA GROUP culture.

At the same time, however, we also see our company as an entity with a clear Greek footprint and a real connection to the domestic ecosystem. We do not simply want to “make sales”, but to contribute to strengthening the Greek technological and defence base and to be part of the country’s growth.

We want to evolve together with Greece, just as our Greek team evolves together with our company: with development, steady progress and the creation of real know-how that stays in our homeland.

Let us not forget that the Greek language, through its structure, depth and complexity, has over time cultivated a particularly advanced way of thinking. Since antiquity, the ability to describe complex concepts and difficult ideas precisely, through a language that “withstands” this complexity, acts as a mental exercise that builds speed, clarity and analytical ability. This way of thinking, deeply rooted in the Greek-speaking world, is something we believe is reflected in the Greek-speaking engineers we focus on.”

What is coming in defence technology in 2026

In general terms, last year defence technology was one of the sectors that attracted the most capital at European level, with investor interest focusing particularly on dual-use technologies.

Asked whether he thinks this trend will continue in 2026, the CEO of STHENOS AI replied that “based on the international situation, I believe that in 2026 our field will grow even further, with more growth opportunities and new technologies maturing. Developments in the defence sector have also offered a great deal at civilian level in the past.

Technologies and ideas originally created for defence found commercial applications and raised living standards and productivity. GPS, the Internet and radar are some of these technologies.

In 2025, Artificial Intelligence was clearly the biggest technology topic in defence, and personally this has brought me joy, but also concern about how these funds will be invested in Europe this year.

Companies and large organisations without a real focus on Artificial Intelligence, in particular, often underestimate its difficulty: they see it as something “simple” and try to cover it by hiring 2–5 people without the necessary expertise or without knowing how to properly build a capable team. So when a serious project comes along, they cannot deliver, because they simply do not have the right “DNA” to take on projects at that level.

Often, too, the necessary physical and technological infrastructure for the secure development of these solutions is missing, something that in defence projects is just as critical as the software itself, and something we are proud to have been the first in Greece to bring to such a serious technological level.”

On the other hand, Mr Hatziminas pointed out that “there is also the opposite problem: overestimating what Artificial Intelligence can do, which leads to requirements that in some cases are practically impossible to deliver within such budgets and timeframes, creating false expectations and ultimately disappointment for organisations and public bodies investing in such solutions.

In such cases, what is even more interesting is that organisations without this technological level accept these specifications without realising that they will ultimately not be able to deliver them.”

“Another technology I strongly believe will stand out is quantum technology, with an emphasis on quantum sensing for space defence applications, as it can offer sensors with much more and more accurate data. Also quantum cryptography for encryption and decryption, which in my opinion is the future in these areas.

An interesting point is that many governments are already storing vast volumes of data, expecting that within the next 10 years they will be able to decrypt them through quantum capabilities.

We are already researching how quantum technology can be applied to our systems, through a specialist we have hired who works alongside our Machine Learning engineers and researches in parallel together with our group,” he added.

The dynamics of the Greek defence market

Regarding the Greek defence market, the CEO of STHENOS AI said the company views it “very positively, and we are particularly pleased that in recent years Greece has made a serious effort to strengthen its domestic defence and technology base, giving space and real power to people and organisations such as ELKAK (Hellenic Centre for Defence Innovation).

“At the same time, what I observe is that through the concept of “dual use”, many Greek companies are leveraging technologies that start in the civilian sector and evolve into defence applications, as a more natural way of entering these markets. This is gradually creating greater domestic capability, making the country more independent and strengthening Greece’s self-investment in technology and know-how, as well as in the Greek workforce,” he added.

Plans for the future

Finally, regarding the company’s plans for 2026, Georgios Gkekas revealed that “it will be the turning point for STHENOS, as January marked the start of work on two very important products. However, since technology on its own is not a solution to the most important problems of our society, we too, together with the other companies of the group, must promote a collaborative model with our customers.

This is something not often found in projects of this kind, where the contracting authority and contractor model dominates. We firmly believe that only a collaborative model, in which the customer designs and implements the solution together with us, will deliver the maximum benefits and succeed in integrating complex technologies such as Artificial Intelligence into the highly sensitive field of defence. And that is where STHENOS AI will help the most, as it was created with exactly this DNA of flexibility and rapid adaptation.”

Read the original article on Euro2day.gr→