Dekmantel

Dekmantel is a Dutch electronic music festival. I built its companion app in React Native and Expo: a local-first product that gives visitors their tickets, line-up and schedule, and keeps working even when connectivity on the festival grounds drops to nothing.

The core challenge was reliability under bad network conditions. I designed the app around a local-first architecture, where data is cached on-device and synced before and during the event, so the experience stays fast and fully usable offline. Tickets are delivered as scannable QR codes through the API, and I built the sync and caching strategy so everything visitors need is already on their phone by the time they arrive.