Resilience isn’t just about cybersecurity or protecting systems; it’s about how organizations adapt when everything around them changes. It touches supply chains, team availability, market shifts, regulations, and even reputational challenges.
This broader view shaped Leaseweb’s TechSummit 2025 in Amsterdam. Under the theme “Building Resilience at Scale,” the event highlighted resilience as a strategic necessity, not just a technical one. Companies that invest in resilient systems, teams, and processes today are better equipped to handle the unexpected tomorrow.
The speakers all brought a unique perspective on what building resilience means to them. After listening to them all, it was clear there were 4 categories we could split the speakers into.
1. Predictive Infrastructure
As we all know, technology is moving fast, but innovation alone isn’t enough; resilience is what really matters. Complex systems need to stay precise and reliable, even as they scale and handle more demanding tasks.
That point became prominent in several of the speakers’ presentations. From global defence to advanced manufacturing, this was the key theme. Michael Street from NATO explained this perfectly when he said:
“Resilience for us extends beyond cybersecurity. It’s about ensuring that systems, people, and nations can continue functioning under pressure.” – Michael Street, NATO
What stood out to me in Michael’s presentation was how resilience at NATO isn’t just about protecting systems, it’s about sustaining function in the most demanding environments. That same principle applies to how we design digital infrastructure: communication, continuity, and adaptability.
We saw a similar mindset in Max Adaloudis’ presentation from ASML, where the challenge isn’t geopolitical, but deeply technical, building machine learning systems that can make sense of enormous volumes of data while remaining explainable and reliable.
“Our biggest hurdles are high dimensionality, physical complexity, and the need for interpretability.” – Max Adaloudis, ASML
The lesson is clear: resilience in complex environments is about staying precise and reliable, even when there’s almost no margin for error.
Predicting challenges is one thing, but preventing them is even better. That’s what architectural resilience is about: building systems that keep running smoothly, no matter how complex they get.
2. Architectural Resilience
Something apparent in the talks given around this topic was that architectural resilience isn’t just about avoiding failure, but rather ensuring the system is able to recover from it – or preventing failure in the first place. Some of the latest architectures are living ecosystems of microservices, APIs, and event streams. They evolve fast, but that speed can become fragile if you can’t see or control how all the moving parts interact.
What stood out to me in both Mourjo and Marc’s presentations is how they both approached resilience through ‘visibility and reliability’. To understand where your risks and potential bottle necks lie can only be done by creating visibility from the start.
As Mourjo Sen put it:
“We build systems for our customers, so we need to measure what really matters, and that’s the customer experience.” – Mourjo Sen, Booking.com
Reminding us how important user impact is. Sometimes we are so focused on the technical metrics we overlook what may make the difference here. It is not always the case that these metrics can be trusted as Mourjo explained:
“A service can respond in milliseconds and still create timeouts if you’re not observing the full chain.” – Mourjo Sen, Booking.com
This theme of visibility was carried through into Marc’s presentation, to look at the ‘full picture’ in order to create a ‘durable’ or resilient system. He described how distributed systems that span over multiple workflows and services are the key to ‘durable execution’:
“Durable execution is about bringing reliability to stateful applications, making sure that workflows survive crashes, redeployments, or even full system restarts.” – Marc Klefter, AxonIQ
The presentations take on a new perspective on what resilience means in an architectural sense. It is about designing for continuity, even when some systems fail, you are still able to serve your clients.
Of course, architecture alone isn’t enough. Even the most durable systems are only as resilient as their security foundations, and that’s where security and orchestration come in. Security is key. Large systems are complex and layered security and careful coordination help keep everything running safely.
3. Security & Orchestration
2025 has been a major year for security. With technology booming and systems scaling faster than ever, the big question remains: can we grow at this pace while staying secure? You can’t scale safely if your defences don’t scale too, and the larger the system, the harder it is to track what matters.
What stood out to me across all four security sessions was how aligned they were on this idea. Whether the speakers were talking about authorization, automation, cloud foundations, or incident response, they all pointed to the same shift: resilience comes from coordination, not accumulation. As Sohan Maheshwar explained when discussing Zanzibar, global-scale systems only stay secure when authorization decisions remain “fast, correct, and globally propagated”, consistency becomes a resilience feature.
That theme continued with Marco Pierobon, who argued that security at scale is really an orchestration challenge. Automation gives you speed, but resilience comes from knowing where humans need to step in. And when systems inevitably come under pressure, Arjen Wiersma reminded us that the goal isn’t to lock everything down, but to build systems that can “recover, reconfigure, and continue operating even under attack.”
All this ultimately depends on having the right foundation. As Prerit Munjal put it, resilience must be built in from the architectural level, not patched on later. Strong infrastructure gives you something stable to rely on.
For me, the takeaway is simple: scaling securely isn’t about adding more defences, it’s about designing for resilience from the start, making sure every layer of the system can adapt as quickly as it grows.
4. Operational & Human Resilience at Scale
In a world where it feels technology might quite literally be taking over. Kaustubh brought up some excellent points on how technology alone can’t guarantee continuity. Resilience is more about how teams respond when things go wrong. Not everything is about uptime as we may think! A reminder that the most reliable systems are built by teams that can absorb change without losing momentum.
I enjoyed Kaustubh’s presentation, which emphasized that resilience is both a human and technical challenge. Even the best resilient system can fail if the team can’t adapt.
As he puts it:
“Resilience isn’t just about systems that heal themselves, it’s about teams that can adapt when everything changes around them.” – Kaustubh Hiware, Mercari
The importance of bridging time zones and aligning on incident reports becomes apparent. Operational resilience depends on shared understanding just as much as it does on system design. That is where the true resilience is seen, in a team that can work with their systems to better the customer journey.
TechSummit showed that resilience isn’t just one layer; it’s how systems and teams anticipate, adapt, and recover. As architectures grow more complex, it’s easy to add layers, but the real challenge, and opportunity, is designing thoughtfully. Sometimes, less really is more. It was inspiring to share ideas with so many brilliant minds and explore resilience from every angle.
Make sure to come to our next TechSummit edition on September 30th, 2026.
If you missed TechSummit 2025, make sure to watch the highlights below: