Thursday evening, 25 June. After three days of Power BI Summer School, we are safely back home after a four hour drive in the heat. Miraculously, both physically and mentally — although the mental part is still being validated in Power Query. 🚀
What an amazing edition it was once again!
With an incredible amount of new information that we tried to save onto our own internal hard drive — hopefully without triggering a refresh error — we put our bag against the wall and greet our children and wife. 🧠💾🏡
They vaguely remember us. We vaguely remember normal family life.
And yet… there is already that strong urge to open the laptop again and start testing all the new material in detail. Because apparently, after three full days of Power BI, the only logical next step is… more Power BI. 😊
But let us first take a moment to look back on the past few days, before our brain archives everything under “Miscellaneous”.
Monday evening 22/06/2026
Do you remember that feeling as a child when, every summer, you would meet your holiday friends again after an entire year? Something very similar happens at Summer School — only now with more DAX, fewer sandcastles, and slightly more back pain.
10:00 PM: This year, we arrived at the Fletcher Hotels in Callantsoog. Due to circumstances, we could only join the group quite late. The others had already enjoyed an extensive introduction session at the beach pavilion, which is a polite way of saying they were already several conversations, drinks and inside jokes ahead of us.
Still, when we walked into the hotel lobby at around 10:30 PM, it almost felt as if people had been waiting for us. Luc Debois shouted across almost the entire lobby: “Wim!” 😄
A subtle, discreet entrance. The atmosphere was clearly already excellent, and we were very happy to see so many familiar faces from previous years. Warm greetings and hugs were handed out immediately. The newcomers quickly understood what a close-knit group this has become — and possibly wondered whether they had accidentally joined a data-themed family reunion.
From what we heard, this edition was completely sold out. KPMG even showed up this year with eight participants — undoubtedly thanks to the positive publicity from Anouk Goos. Or perhaps because someone told them there would be BBQ, boats and Belgian chocolate. Both are valid business cases. 😉
Tuesday
8:00 AM: We start right on time at 8:00 AM. Dutch efficiency, as always. ⏰ As a Fleming, this remains impressive and slightly intimidating.
Just like last year, Michiel Rozema had the honour of opening the event with the first session: What’s New in Power BI & Fabric. Straight into the latest updates. Staying informed about new developments is exactly what a trainer should do — even if Microsoft seems determined to release new features faster than we can open Teams.
After narrowly missing out two years ago, he was finally there this year: the one and only Dutch Data Dude, Jeroen ter Heerdt. Fresh from Norway, probably still slightly cooled down and therefore perfectly suitable for explaining Calendar-based Time Intelligence.
Jeroen convinced us that calendar-based Time Intelligence is much better than the regular calendar options in Power BI. And he did so, as always, with tremendous energy and enthusiasm. He clearly picked up a bit of that American presentation style during his years in the States. Luckily without requiring us to clap every 12 seconds. Almost.
After lunch, the ever-friendly Melissa de Korte, whom we had already met in London during the Global Excel Summit, finally gave a session on Power Query.
And honestly: why are these sessions so rare? You can find DAX training everywhere, but training on M functions? Much less often. Apparently, Power Query is like that one brilliant colleague everyone depends on but nobody invites to the strategy meeting. 💚💛
And yet Power Query is such a brilliant feature in both Excel and Power BI — quietly cleaning up everyone’s mess while DAX gets all the applause.
Fortunately, there was also plenty of time for individual questions during the Q&A sessions. We made full use of that opportunity, especially with some of Europe’s leading Power BI experts gathered in one place. Because when else do you get the chance to ask your impossible question and watch several experts simultaneously stare into the distance? 😊
Traditionally, Mark van Kimmenaede, Ad Kamsma, Hendy de Geus – Kanters and Robert Speulstra were the usual suspects to the questions and business cases to present. At this point, they are no longer participants; they are basically the extended exam committee.
After eight hours of training, our own hard drive also needed a little rest. Luckily, the hotel offered plenty of options. The sporty participants went jogging, walking, playing pool or even swimming afterwards. Those who preferred a slightly calmer recovery method went straight for an aperitif on the terrace. 🍹
Both groups called it “recovery”. Only one group was honest.
After eight hours of training, the BBQ at the nearby beach bar De Stern tasted absolutely delicious. By then, even a calculated column would have tasted good, but fortunately the food was much better than that.
We ended the day with a beach walk during a beautiful sunset. 🌅 Very inefficient from a step-count perspective, but excellent for the soul.
Wednesday 24/06/2026
Once again, we started promptly at 8:00 AM, this time heading into the more technical sessions. Because apparently Tuesday was only the warm-up. A gentle appetizer. A little DAX amuse-bouche.
Marthe Moengen presented her session: When AI Meets Power BI: Copilot, MCP Servers, and the Future of Analytics. AI remains a challenging topic: how exactly will we use it in Power BI and Fabric in a practical way? Preferably in a way that does not start with “Just click Copilot” and end with “Please fix everything manually anyway”. One can not say Marthe does not have dedication, bringing her own husband and young baby to the event.
Traditions are there to be honoured. Henk Vlootman presented, as he does every year, a highly technical session — this time on Translytical Task Flows and Input Slicers.
If there is one thing you have to give Henk credit for, it is that he always happily takes on the most technically difficult session himself. With almost a century of experience, this is of course child’s play for him. 😉🧓📊
After lunch, our brains needed to cool down again, despite the heat. Michiel and Henk had judged this perfectly, because we literally went out to get some fresh air on three boats in the harbour of Den Helder during the famous Mystery Tour. ⛵
Armed with plenty of sunscreen, a lunch package and some seasickness pills, the whole group boarded three ships taking us to Texel — or “Tessel”, as the Dutch themselves pronounce it, just to keep foreigners alert.
On board, the atmosphere was fantastic, with pickled herring and jenever. Honestly… this was pure enjoyment! 🐟🥃☀️
After the car ride back, it was time to network at the beach bar. Those who felt like it — and there were quite a few — again organised a little sports moment for themselves. The high temperatures, combined with a nice breeze, once again encouraged the sporty participants to go walking, jogging or swimming. Each year, we manage to convince more participants to go jogging (or “hardlopen” as the locals call it), some promised to bring their shoes next year!
The rest of us continued our strategic hydration programme.
We ended the day with a lovely dinner. Even during the meal — or perhaps precisely because of the food and drinks — the data analysts continued dreaming out loud about new data models, DAX functions, automation and so on.
It was very clear: these people truly love their job. ❤️📊 Or at least they have developed a very advanced coping mechanism.
Thursday 25/06/2026
Already the final day. And once again, 8:00 AM sharp. At this point, even our alarms had started speaking Dutch.
Michiel showed us the new Power BI feature: UDFs — User Defined Functions. Finally, time to learn and use this “new” application. And what did we discover? Quite handy indeed! 👌 Which, in Power BI language, means: “This will probably save us hours, after we spend days figuring out when to use it.”
The second Q&A session brought us back to some familiar old questions. Even for all these experts, some questions still seemed impossible to solve — with thanks to Mark van Kimmenaede. 😄 It is always comforting to know that some problems are not bugs in your own understanding, but simply shared trauma.
Luc Debois — yes, there was another Fleming in the room — naturally could not resist thanking the speakers and organisers with Belgian chocolates. And to be fair, they absolutely deserved them.
A big round of applause from everyone for the excellent organisation. What a fantastic few days of learning and enjoyment it has been.
Madzy Stikkelorum-Groenveld had the honour of closing the event with a particularly popular topic — one we had all been looking forward to. A perfect ending, because after three days our brains were full, our notebooks were full, and our list of things to practise had become emotionally damaging.
And once again, we gained so much knowledge.
If we may add one small negative note — the same one as last year — when on earth are we going to find the time to practise all of this? 😊That’s why we have another year until the following edition.
Once again, huge congratulations to Quanto, and in particular to Michiel Rozema, Henk Vlootman, Oscar Eroumé, Laura van Leuven, Madzy Stikkelorum-Groenveld, and all the speakers: Marthe Moengen, Jeroen ter Heerdt and Melissa de Korte, for their more than valuable and inspiring contributions. 👏
The dates for 2027 are already available and have been noted in the calendar… which we still need to create, of course. 😊📅
What a pity that we have to wait another full year to see our Power BI Summer Holiday friends again. 😊
Although, to be honest, our brains may need exactly that long to finish refreshing. 🔄🧠
