It was a Friday we’ll never forget — the day the biggest ticket sale in Croatian history kicked off. Actually, it wasn’t just Croatia: when it comes to one artist, …
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It was a Friday we’ll never forget — the day the biggest ticket sale in Croatian history kicked off. Actually, it wasn’t just Croatia: when it comes to one artist, one concert, it was one of the largest in the world.
It’s not just the numbers we’ll remember. We will remember how everything came together: the preparation, the execution, and the real-time system management while nearly an entire nation raced to secure a ticket for Marko Perković Thompson’s concert at the Zagreb Hippodrome.
This is the story from behind the scenes — a firsthand look at one of the most intense days in the region’s ticketing history.
Quick Preparation, Dynamic Execution
Planning for the ticket launch began just six weeks before sales day. Even the figures we pulled during prep couldn’t predict the real demand. We had guessed up to 100,000 tickets might sell. The actual number? Almost five times that.
Early estimates were conservative, and the office joke was, “Let’s not jinx it by overestimating.”
Every Entrio team — from development to customer support — was all-in.
Project management coordinated tasks and adapted on the fly. Customer support? The moment news about Thompson’s concert went public, our inbox exploded. Normally, we handle around 1,000 inquiries a month — for this concert alone, we received over 7,000.
Meanwhile, our marketing team’s first-weekend reach on social media? Over 3.8 million views, nearly 2 million users, and more than 16,000 interactions.
And that was just the beginning. After the weekend, news concerning the concert dominated media — from news portals to TV.
Development and IT had been gearing up for months, learning from last year’s experience with Thompson’s concerts in Imotski and Dugopolje.
Right up to the final hour, seating charts, maps, and layouts were tweaked to ensure fans knew exactly where they’d sit — and how to navigate buying a ticket.
Technical Preparations: A Developer’s Perspective on Biggest Ticket Sale
Over the past nine months, Entrio completely modernized its infrastructure. We migrated from virtual servers to modern cloud services, allowing seamless scaling without downtime.
Wherever possible, we now rely on serverless architecture.
For this specific concert, two months of load testing simulated tens of millions of transactions — pushing every part of the system to its limits.
“In test mode, we ‘sold’ more tickets than there are people in Croatia — all without breaking a sweat on the staging environment.”
One of the key milestones was breaking apart our monolithic system: splitting it into smaller services that could scale and be monitored independently. We also implemented a virtual waiting room — a system that controlled traffic flow during peak times and ensured fairness and stability.
Sales Day: Inside the Real-Time “War Room”
Sales day arrived.
We taped a notice to the office door: “Tickets are not sold at this location.”
Still, a dozen eager fans showed up. We politely redirected them to nearby ticket outlets.
While fans knocked on our door, behind the scenes we were facilitating ticket sales on a global scale.
The entire office was buzzing — development, DevOps, support, management — even team members flew in from other cities and countries.
Real-time dashboards tracked everything: system performance, ticket sales, load, errors.
Even though the official start time was noon, by 9 AM we already had four times the usual peak traffic.
At one point, Cloudflare detected 1.2 million devices trying to access our system simultaneously.
Laptops, phones, tablets — people were using everything they had to get a ticket.
The system handled 80 times more requests per second than usual.
Our infrastructure advisor Luka Kladarić described it perfectly in an interview:
“People had laptops and four phones open at once in the waiting room. It was a massive load. And the worse the system performed, the more people refreshed, adding even more pressure.”
Despite everything, the system stayed up for hours under this insane load.
One big help? The concert organizers were tech-savvy themselves, understanding technical terms like “load test,” “bottleneck,” and “scaling.” Thanks to that, we coordinated decisions quickly, stayed calm, and kept realistic expectations.
We also kept fans updated with real-time announcements on social media — transparency was key.
What Else Was Happening That Day?
Of course, Thompson’s concert wasn’t the only event being sold on our website.
It was Friday — meaning other organizers were preparing weekend events, too. Big shows like Bijelo Dugme’s sold-out Arena Zagreb concert needed flawless ticket scanning.
Our system was under enormous strain — impacting all operations. Through clear communication and support from event organizers, we avoided major issues.
Even global giants like Ticketmaster struggled that weekend, facing massive queues and system crashes during Lady Gaga’s UK ticket sales.
Lady Gaga fans have slammed Ticketmaster after struggling to secure pre-sale tickets for her Mayhem Ball, with many reporting being kicked out of queues for being flagged as 'bots.' The star’s UK and Europe tour, which includes her first UK shows since 2022, faces criticism for pic.twitter.com/xb4hOLDJZg
— IBTimes UK (@IBTimesUK) April 2, 2025
anyone already reselling their lady gaga tickets while we're all fighting that stupid ass Ticketmaster website that keeps crashing I hope you never get tickets for anything ever again
— ani (@ina_IK) April 3, 2025
This shows that massive ticket sales aren’t just a local challenge — they’re a global one. Success today depends not just on scalable infrastructure, but also transparent communication and real-time adaptability.
Lessons Learned and Adjustments for the Next Sale
After the first day, we dug deep into system logs and analytics.
We made key optimizations before the second round of ticket sales — including new isolated services for ticket outlets and faster detection of slow queries.
The second sale, held on April 3, went even smoother — 25% more successful transactions and significantly fewer issues.
We also proactively answered common customer questions directly in the waiting room messaging — reducing support pressure and calming nerves.
The Real Challenge Wasn’t Selling Tickets
Selling a record number of tickets wasn’t the real challenge.
The real challenge was selling them all at once — while tens of thousands of people believed they only had one shot.
“People kept refreshing out of fear, multiplying the traffic into chaos.”
And yet — the tickets sold.
It wasn’t perfect. The system slowed, and at times, became briefly unavailable.
But thanks to an incredible team — and patient fans and organizers — we powered through and set a new record, solidifying Entrio’s place as the leading ticketing platform in the region.
What Made This Success Possible?
Aside from technical preparation, organizational flexibility and a calm, coordinated team were key.
And, of course, the power of the artist.
Thompson’s current cultural relevance created an unprecedented surge of interest.
“To put it in perspective: in just one hour, 50,000 tickets were sold — that’s like selling out three Zagreb Arenas or one major Champions League stadium!”
What Now, After the Biggest Ticket Sale in History?
This wasn’t just another event.
It’s unlikely to happen again — not at this scale, not with this intensity.
For organizers, media, and the industry, it’s crucial to understand: these events demand not just technical capacity, but mental resilience, technical flexibility, and operational readiness.
We jokingly asked Timotej Perčič, the project manager, whether every future concert would now feel small compared to this success.
“Of course, we’re kidding — but the perspective does shift. Selling several thousand tickets in under 24 hours is a huge success, and always will be.
No matter the size of the event, our respect and attention remain the same — from the smallest gatherings to the biggest shows.”
Author: Franjo Opačak
