Full Stack Web3 developer.

# Senior Web3 Developer - Full-Stack Integration

**Location:** Remote
**Type:** Contract/Freelance
**Budget:** $4,000 - $10,000
**Timeline:** 3-6 weeks

## **About FHEGuess**

FHEGuess is a groundbreaking privacy-preserving number guessing game built with Zama's FHEVM (Fully Homomorphic Encryption Virtual Machine) technology. Players submit encrypted guesses that remain completely hidden throughout the game, ensuring true zero-knowledge gameplay where no one - not even the game host - can see the guesses until results are revealed.

**???? How it Works:**
- Players guess numbers between 0-100 during odd hours (13:00, 15:00, 17:00...)
- All guesses are encrypted on-chain using advanced FHE technology
- Results are revealed during even hours (14:00, 16:00, 18:00...)
- Closest guess to the secret number wins

**???? Current Status:**
- Smart contracts deployed and functional on Sepolia testnet
- Basic React frontend with wallet integration
- Express backend with MongoDB ready for integration
- Needs full-stack Web3 integration and feature completion

## **Project Requirements**

We need an experienced Web3 developer to integrate our blockchain game with traditional backend services, creating a complete gaming platform with enhanced user experience and social features.

## **What We Need**

### **Frontend Integration**
- **Wallet Connection Enhancement** - Multi-wallet support (MetaMask, WalletConnect, Coinbase)
- **Real-time Updates** - WebSocket integration for live game state
- **Error Handling** - Comprehensive transaction error management
- **Loading States** - Professional loading indicators and transaction status
- **Mobile Optimization** - Responsive Web3 interactions

### **Backend Integration**
- **User Management** - Connect wallet addresses to user profiles
- **Game Statistics** - Track player performance and game history
- **Leaderboards** - Real-time ranking system
- **Social Features** - Player following, achievements, notifications
- **Analytics** - Game performance and user behavior tracking

### **Web3 Features**
- **Multi-chain Support** - Prepare for mainnet and L2 deployment
- **Gas Optimization** - Implement gas estimation and optimization
- **Transaction Management** - Queue, retry, and status tracking
- **Event Listening** - Real-time blockchain event processing
- **Wallet State Management** - Persistent wallet connection handling

## **Required Skills**

### **Core Web3 Expertise**
- **3+ years Web3 development** experience with production dApps
- **Ethers.js/Web3.js** - Advanced blockchain interaction skills
- **Wallet Integration** - Multi-wallet support and connection management
- **Smart Contract Interaction** - ABI handling, event listening, transaction management
- **Gas Optimization** - Understanding of gas mechanics and optimization techniques

### **Frontend Skills**
- **React/TypeScript** - Modern React patterns and TypeScript proficiency
- **State Management** - Redux, Zustand, or Context API for complex state
- **Real-time Features** - WebSocket, Server-Sent Events, or similar
- **Responsive Design** - Mobile-first development approach
- **Error Handling** - Comprehensive error boundaries and user feedback

### **Backend Integration**
- **API Integration** - RESTful API consumption and error handling
- **Database Operations** - Working with user data and game statistics
- **Authentication** - JWT, session management, wallet-based auth
- **Real-time Communication** - WebSocket or similar for live updates

## **Technical Stack**

### **Frontend**
- **React 19** with TypeScript
- **Ethers.js 6** for blockchain interactions
- **Vite** for build tooling
- **TailwindCSS** for styling

### **Backend**
- **Node.js/Express** API server
- **MongoDB** for user data and statistics
- **WebSocket** for real-time features
- **JWT** for authentication

### **Blockchain**
- **Ethereum/Sepolia** testnet deployment
- **FHEVM** for encrypted gameplay
- **Hardhat** for smart contract interaction

## **Key Features to Implement**

### **User Experience**
1. **Seamless Onboarding** - Easy wallet connection and account creation
2. **Game Dashboard** - Personal statistics, game history, achievements
3. **Social Features** - Follow players, view leaderboards, share results
4. **Real-time Updates** - Live game state without page refresh
5. **Mobile Experience** - Full functionality on mobile devices

### **Technical Features**
1. **Multi-wallet Support** - MetaMask, WalletConnect, Coinbase Wallet
2. **Transaction Management** - Status tracking, retry mechanisms, gas estimation
3. **Event Processing** - Real-time blockchain event handling
4. **Data Synchronization** - Sync blockchain data with backend database
5. **Performance Optimization** - Efficient API calls and state management

## **Deliverables**

1. **Integrated Frontend** - Complete Web3 frontend with backend connectivity
2. **User Management System** - Registration, profiles, authentication
3. **Real-time Features** - Live updates, notifications, game state sync
4. **Mobile-Responsive Design** - Full functionality across all devices
5. **Documentation** - API integration docs and deployment guide
6. **Testing Suite** - Unit tests for critical Web3 functionality

## **Preferred Experience**

- **Gaming dApps** - Experience with blockchain gaming projects
- **DeFi Protocols** - Understanding of complex Web3 user flows
- **Real-time Applications** - WebSocket, live data, and state synchronization
- **Mobile Web3** - Mobile wallet integration and responsive design
- **Performance Optimization** - Large-scale dApp optimization experience

## **Project Phases**

### **Phase 1: Core Integration (Week 1-2)**
- Multi-wallet connection system
- Backend API integration
- User registration and profiles
- Basic game statistics tracking

### **Phase 2: Enhanced Features (Week 3-4)**
- Real-time updates and notifications
- Leaderboards and social features
- Mobile optimization
- Advanced error handling

### **Phase 3: Polish & Testing (Week 5-6)**
- Performance optimization
- Comprehensive testing
- Documentation and deployment
- User acceptance testing