The benefits of cloud, yet on-prem

Published on 23/04/2025 in Expert talks

On-premise infrastructure is back! Its advantages can now be combined with those of the public cloud. Tom Olislagers (Dell Technologies) frames the evolution together with Thierry Van Nuffelen and Filip Marchal of Proximus NXT.

The benefits of cloud, yet on-prem

“Many enterprises have moved to the public cloud, with workloads, in recent years,” says Tom Olislagers, CTO for western Europe at Dell Technologies. “They were often greenfields, where they could deploy new processes. Today, while they still want the benefits of the cloud, such as easy management, they also want the sovereignty and security of an on-premise environment. To that end, they roll out on-prem cloud stacks, within ecosystems such as Microsoft, VMware, Nutanix or Red Hat OpenShift.”

Why the return to on-prem?

One major reason why companies are partially moving away from public cloud and interest in on-prem is growing again is cost. “Twenty years ago, companies chose the public cloud because they wanted to move from capex to opex,” Tom says. “Large investments in their own data centers were replaced by an environment with only operational costs. Looking back, it didn't turn out to be cheaper after all. On the contrary, on-prem has always remained quite cost-effective.”

Valéry Vander GeetenTom Olislagers
CTO West-Europa at Dell Technologies

“On-premise never completely disappeared from the scene,” Thierry Van Nuffelen, Product Manager Cloud at Proximus NXT, says. “For certain customers, it always remained the way forward and still does, and the number of companies opting specifically for on-prem is increasing. Partly because on-prem costs are easier to predict.”

Control over data

There is also a growing realization that some workloads are better left on-premise. “For example where a user experience with low latency is important,” Thierry notes. Companies that are now experimenting with AI but have not yet developed a business plan around it often reach for the public cloud. “You can quickly build an AI model on that,” Thierry says.


There are solutions that let you use IT infrastructure and services 'as a service,' just like in the public cloud, but with all the advantages of on-prem.

Tom Olislagers, CTO western Europe at Dell Technologies.


“But companies that have been working with AI for a while are usually more aware of the data sets they are working with – and thus also of the potential risks when you store those data sets in the public cloud.” At the same time, there is also a practical consideration at play here and that plays a part in determining costs. After all, it makes more sense to use your AI model on your on-prem data, instead of having to send all your data to the cloud because your AI application is running there.

“Again, usage costs also fall easier to estimate if you keep it entirely on-prem,” Tom continues. “All the more so if we deploy thinking AI models where the consumption level is difficult to predict in advance. Also, the more you add your own data to the AI model's dataset, the more that increases the quality of the answers you get. But if you do that in the public cloud, you expose your data to the provider. If you work on-prem, you retain control of the data and access to it.”

Awareness is growing

“Companies like Microsoft are investing a lot in the security of their public cloud,” Filip Marchal, Private Cloud Lead at Proximus NXT, says. “But, as a user, you still have to link the puzzle pieces of your own environment and the cloud piece together. Something that companies don't always understand. With on-prem, they do understand that the responsibility for IT security lies with them. Certainly given the geopolitical situation. But that understanding is still much smaller for the public cloud.”

Valéry Vander GeetenFilip Marchal
Private Cloud Lead at Proximus NXT

“The awareness around the importance of sovereign cloud and cybersecurity is also increasing thanks to the European NIS2 regulations,” Tom continues. “Companies must be able to start up a minimal but workable IT infrastructure in the event of a digital attack quickly and thus keep their business operations running. We then build a minimal viable system for that purpose: the minimum amount of applications, stored in a vault, that a company needs to restart after an attack.”

“For many companies, sovereign cloud may still sound a bit vague as a concept, but its basic concepts are essential for numerous companies,” Thierry emphasizes. “Keeping applications in-house, knowing where the datasets are and who has control over them, controlling the operational management of processes end-to-end ... This awareness in Europe is greatly increasing. The U.S. election accelerated it. How do you make sure your IP and data remain your property? That insight is clearly growing now.”

Valéry Vander GeetenThierry Van Nuffelen
Product Manager Cloud at Proximus NXT

How do you specifically make that happen?

The solution is in an on-prem sovereign cloud. “We build that on a Dell APEX Cloud Platform,” says Tom. This is where the partnership with Proximus NXT, which last year received the Dell Technologies' APEX Partner of the Year Award, comes in. “APEX is a platform that allows companies to use IT infrastructure and services 'as a service’, just like in the public cloud,” Tom explains.

“But this is done with more control using on-prem in an in-house data center or via colocation in a partner's data center, such as Proximus NXT, each time on Belgian territory, on a platform of your choice.” The solution thus offers the best of both worlds: the benefits of private infrastructure and the advantages of the public cloud. “For example, you only pay for what you use,” Tom says. So cloud-like consumption on-prem: the consumption model of the cloud, together with the advantages of on-prem, but without the classic investment.


Some workloads are better left on-prem, for example, because the user experience demands low latency.

Thierry Van Nuffelen, Product Manager Cloud at Proximus NXT.


Control over your own AI workload

Dell developed a custom solution specifically for getting started with AI on-prem - or via colocation “It involves Dell AI Factory, a suite that allows companies to set up AI models locally and run them in an on-prem cloud,” Tom explains. “To simplify the process, we provide validated templates for frequently recurring use cases: pre-engineered, pre-integrated and pre-tested for smooth integrations with NVIDIA, AMD and Intel, for example.”


The partnership with Dell is focused on the total unburdening of our customers.

Filip Marchal, Private Cloud Lead at Proximus NXT.


Dell Technologies and Proximus NXT are therefore jointly responsible for IT security. Filip: “Together with a partner like Dell we build infrastructure, not only on-prem, but also in the edge, which we then manage, maintain and update, including all the necessary services around optimal security. Together, we equally implement a hybrid environment or even a complete on-prem sovereign cloud, with all the accompanying efforts for optimal security and resilience.”

That way, Dell and Proximus NXT together offer a one-stop shop. “We bundle our years of experience and expertise around local needs,” Filip concludes. “Complete unburdening, that's what it's all about in the end.

Want to know which cloud environment best suits your business?

Take the test Opens a new window

Filip Marchal is Private Cloud Lead at Proximus NXT. He has over 20 years’ experience at Proximus NXT, in various technical, consultant and management roles around cloud and security.

Tom Olislagers is CTO for western Europe at Dell Technologies. He started his career as a Solutions Architect at IBM. He joined Dell in 2013 where – after a brief interlude at UCB – he advanced to CTO.

Thierry Van Nuffelen has fifteen years’ experience at Proximus NXT, including the past five years as Product Manager Cloud. He supports the digital transformation of companies, focusing on sustainable growth and efficiency.