Heist Danmark App
Interactive survey and rewards app where users earn $HOINS coins to bid in live-streamed auctions or shop in the integrated marketplace.
Visit heist-danmark.comSurvey & Live Auction Platform
- Client
- Heist Danmark
- Year
- 2024
- Timeline
- 10 months
- Team
- Mobile Developer (React Native), Backend Engineer (.NET Core), UI/UX Designer, QA Engineer
The idea behind Heist Danmark App
Heist Danmark combines surveys, rewards and shopping in one app. Users complete surveys to earn $HOINS, then spend them in the HEIST store or bid with them in live auctions. Wallet history, notifications and profiles tie it all together.
Live auctions are the demanding part. With thousands of people watching and bidding, each participant's stream, current bid and balance have to stay in step. The app includes live chat, auction alerts and bidding history alongside the survey and store flows.
The stack spans React Native, React.js, Node.js, .NET, PostgreSQL, Redis, Socket.io and WebRTC. Redis pub/sub carries the realtime features, and auction state stays in sync across mobile and web. Bids show on screen instantly and are then confirmed by the server, and every $HOINS transaction is recorded so it can be audited. Survey answers are screened for fraud patterns so the research data stays usable.
Built with
- React Native
- React.js
- Node.js
- .NET
- PostgreSQL
- Redis
- Socket.io
- WebRTC
- Push Notifications
What we built
- Live-streamed auction events with real-time bidding
- Interactive survey platform with instant $HOINS rewards
- Integrated e-commerce marketplace
- Real-time token wallet and transaction history
- Live chat during auction streams
- Push notifications for upcoming auctions and surveys
- User profiles with bidding history and achievements
- Social leaderboards and gamification elements
What was hard, and how we solved it
The hard parts
- Maintaining sub-second latency for live auction bids across global users
- Preventing survey fraud and ensuring data quality
- Scaling WebRTC streams to thousands of concurrent viewers
- Managing real-time token economy without blockchain overhead
- Synchronizing auction state across mobile and web platforms
- Handling payment processing for both token and fiat transactions
What we did about them
- Implemented Socket.io with Redis pub/sub for horizontal scaling of real-time features
- Built WebRTC infrastructure with multiple quality tiers and automatic fallback
- Developed fraud detection algorithms analyzing survey completion patterns
- Created optimistic UI updates with server reconciliation for auction bids
- Designed event-sourcing architecture for audit-able token transactions
- Integrated CDN with adaptive bitrate streaming for global auction delivery
- Implemented queue-based survey distribution to prevent spam
After launch
- 100,000+ completed surveys with 85% completion rate
- 15,000+ active users participating in auctions weekly
- €500K+ worth of $HOINS distributed
- 500+ successful auction events with 97% uptime
- Average of 2,000 concurrent viewers per major auction
- Partnership with 50+ research companies
- 4.6★ average app store rating
Inside the app
Select a screen for a closer look.
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