Blockchain Full stack developer

Tech Stack

• Blockchain: Solidity, Polygon (MATIC), Ethereum
• Development: Thirdweb SDK, OpenZeppelin contracts
• Tools: Hardhat/Truffle, Remix IDE, MetaMask
• Testing: Chai, Mocha, Waffle
• Deployment: Thirdweb Deploy, Polygon Mumbai/Mainnet

Key Responsibilities

• Develop and audit Solidity smart contracts for lottery mechanics
• Implement secure random number generation for winner selection
• Build gas-optimized functions for ticket purchasing and prize distribution
• Create admin functions for lottery operators (draw, refund, commission withdrawal)
• Integrate OpenZeppelin security standards and access controls
• Deploy and verify contracts on Polygon network
• Collaborate with frontend team on Web3 integration

Smart Contract Features You'll Build

• Ticket Management: Purchase validation, quantity limits, price calculations
• Random Winner Selection: Secure randomness using block hash and timestamp
• Prize Distribution: Automated winnings calculation and withdrawal system
• Commission System: Operator fee collection and withdrawal mechanisms
• Refund Logic: Automatic refunds for expired draws
• Access Control: Role-based permissions for operators and users
• Event Logging: Comprehensive event emission for frontend integration

Required Experience

• 4+ years Solidity development experience
• 3+ years smart contract deployment on mainnet
• Expert knowledge of Ethereum/Polygon networks and gas optimization
• Production experience with OpenZeppelin contracts and security patterns
• Strong understanding of DeFi protocols and tokenomics
• Experience with Thirdweb or similar Web3 development frameworks
• Knowledge of smart contract testing and auditing practices

Technical Requirements

• Write secure, gas-efficient Solidity code following best practices
• Implement proper access controls and security modifiers
• Handle edge cases and error conditions gracefully
• Optimize contract size and gas consumption
• Write comprehensive unit and integration tests
• Document contract functions and deployment procedures
• Conduct security reviews and vulnerability assessments

Budget: GBP 1800 (Fixed Price)

Proposals: 12 freelancers have applied