Eventfrog Entry App
Mission-Critical Ticket Scanning
Facing an impossible deadline for a 25,000-ticket event, I architected and built this app in under 3 months. The result: flawless, offline-first ticket validation for a smooth entry process, when failure was not an option.
Role | Lead Client-Side Developer / Technical Project Lead |
Timeline | 3 Months (Concept to Launch) |
Tech Stack | Angular, Ionic/Capacitor, TypeScript, IndexedDB, Web Workers, WebSockets |
The Challenge:
A 25,000-Ticket Event and an Impossible Deadline
This project was born from necessity and immense pressure. With a major event of 25,000 attendees just three months away, it was clear: the old entry app would fail under the load. A completely new solution had to be built from scratch, and failure was not an option.
The entire project, frontend and backend, had to be delivered in that tight window by a team of just two engineers. As the sole frontend developer, I was responsible for a bulletproof client application of over 25,000 lines of code that had to withstand this enormous load.
My Approach:
A Bulletproof, Offline-First Architecture
To meet this challenge, the architecture followed one unbreakable principle: absolute reliability, even without an internet connection.
The foundation was a robust offline mode. I used IndexedDB to store all event and ticket data directly on the client device. This meant all critical validation logic—checking for validity and preventing duplicate scans—ran instantly on the device itself, with no server dependency. To keep the UI fluid during intensive data operations, I offloaded all heavy processing to Web Workers.
On top of this foundation, I engineered an intelligent synchronization system. When a network connection was available, WebSockets powered real-time data exchange with the server and, crucially, between all other apps scanning for the same event. If one device scanned a ticket, that information was instantly propagated to all other devices, making fraud impossible. For maximum resilience, the system featured a resume mechanism using a tamper-proof timestamp, with a REST endpoint as a final fallback.
The app was rounded out with real-time statistics and a detailed ticket list showing live status.
The Result:
Flawless Execution Under Extreme Pressure
We met the impossible deadline. The new Eventfrog Entry App was deployed for the 25,000-ticket event, and the check-in process went off without a single hitch. The app handled the high volume of scans with perfect reliability.
Since then, the Entry App has been in tireless operation for Eventfrog every single weekend.
This project is the ultimate proof of my ability to deliver mission-critical software under the highest pressure. It showcases my expertise in:
- Architecting and building complex offline-first applications under tight deadlines.
- Engineering advanced, real-time synchronization with WebSockets.
- Offloading heavy computation to Web Workers to guarantee a responsive UI.
- Delivering robust, enterprise-grade tools that perform under extreme conditions.
Do You Need an Application That Absolutely Cannot Fail?
If your business depends on software that cannot fail, we should talk. I have the experience to architect and build robust, reliable applications that can meet the most demanding requirements.