DeFi Lending Protocol Demo
Solidity + Hardhat + Foundry
Developed decentralized lending/borrowing protocol demo on Ethereum showcasing modern DeFi patterns. Smart contracts (Solidity 0.8.24) implement over-collateralization (150% ratio), algorithmic interest rates based on utilization, automated liquidation mechanism when health factor <1.0, Chainlink price feed integration for real-time asset pricing. React dApp frontend using wagmi + ethers.js for wallet integration. Foundry testing framework with 98% code coverage. Deployed on Sepolia testnet. Demonstrates production-ready DeFi architecture patterns.
The Challenge
DeFi lending requires over-collateralization logic, algorithmic interest rates, automated liquidations, real-time price oracles. Solidity smart contracts need security (reentrancy, overflow). Chainlink integration for price feeds. React dApp wallet integration. Foundry testing critical. Gas optimization needed.
The Solution
Built lending protocol with Solidity 0.8.24 smart contracts. Over-collateralization (150% ratio) protects lenders. Algorithmic interest rate based on utilization. Automated liquidation when health factor <1.0. Chainlink oracles provide real-time ETH/USDC prices. React dApp uses wagmi + ethers.js. Foundry tests achieve 98% coverage. Deployed on Sepolia testnet.
Technology Stack
Architecture
- Solidity lending pool with over-collateralization (150% ratio)
- Algorithmic interest rate formula based on utilization
- Health factor calculation: (collateral * price) / (borrowed * price)
- Chainlink price feeds for ETH/USDC/WBTC real-time pricing
- Automated liquidation when health factor drops below 1.0
- Flash loan implementation with 0.09% fee
- React dApp: wagmi hooks for wallet connection and transactions
- Foundry testing: unit tests, fuzz tests, invariant tests
- Gas optimization: storage packing, unchecked math, assembly
- Hardhat deployment scripts for Sepolia testnet
Key Features
Results & Impact
- Solidity 0.8.24 lending pool contracts with over-collateralization (150%)
- Algorithmic interest rates: utilization-based formula adjusting APY
- Automated liquidation mechanism when collateral health factor <1.0
- Chainlink price feed integration for real-time ETH/USDC/WBTC pricing
- React 18 dApp with wagmi hooks and ethers.js for wallet integration
- Foundry testing framework: 98% code coverage, 150+ unit tests
- Gas optimized: 35% reduction via assembly and storage packing
- Deployed on Sepolia testnet with 100+ test transactions