LendLink

Project Overview LendLink is a comprehensive decentralized lending protocol that revolutionizes how users manage Liquid Staking Token (LST) yields and loan repayments. Built on Etherlink with 1inch Fusion+ integration, LendLink provides a one-platform solution for depositing LSTs, earning yields, and automatically using those yields to repay loans - eliminating manual intervention and maximizing yield efficiency.

The Problem: Current DeFi users face significant challenges: Fragmented Experience: Managing LST yields and loan repayments requires multiple platforms Manual Intervention: Users must manually harvest yields and repay loans Gas Inefficiency: Multiple transactions across different protocols Missed Opportunities: Suboptimal yield harvesting and repayment timing Cross-Chain Complexity: Difficulty accessing yields across different networks

The Solution: LendLink provides a unified platform that: One-Platform Management: Deposit LSTs, borrow stablecoins, and manage yields in one interface Automated Yield Harvesting: Automatically harvest LST yields at optimal intervals Auto-Repay Loans: Use harvested yields to automatically repay loan interest Cross-Chain Functionality: Access yields and loans across multiple networks via 1inch Fusion+ Real-Time Optimization: Continuous yield monitoring and risk management

Key Features

1. One-Platform LST Yield Management

• Unified Interface: Manage all LSTs in one dashboard
• Real-Time Monitoring: Track yield accumulation and performance
• Cross-Chain Yields: Access yields across Ethereum, Etherlink, Polygon, Arbitrum

1. Auto-Repay Loan System

• Automated Repayment: Use LST yields to automatically repay loan interest
• Frequency Options: Daily, weekly, or monthly auto-repay schedules
• Risk Management: Maintain health factors through automated repayments

1. Cross-Chain Functionality

• 1inch Fusion+ Integration: Seamless cross-chain token swaps
• Multi-Chain Support: Ethereum, Etherlink, Polygon, Arbitrum
• Bridge Functionality: Automatic bridging of LSTs and stablecoins
• Yield Cross-Chain: Harvest yields on one chain, repay loans on another

1. Real-Time Analytics

• Dynamic TVL: Real-time Total Value Locked updates
• Yield Performance: Track LST yield rates and accumulation
• Loan Health: Monitor health factors and liquidation risks
• Cross-Chain Stats: Active loans, bridges, and success rates

LendLink is built as a full-stack DeFi application with a microservices architecture that integrates multiple cutting-edge technologies. Here's the detailed breakdown of how everything was pieced together:

Frontend React 18 + TypeScript + Vite + Tailwind CSS ├── State Management: React Query for server state ├── Wallet Integration: RainbowKit + Wagmi ├── UI Components: Custom components with Tailwind └── Real-time Updates: WebSocket connections for live data

Backend Express.js + Node.js + Axios ├── API Gateway: RESTful endpoints with Express ├── 1inch Integration: Custom service layer ├── Real-time Data: WebSocket server for live updates └── Caching: In-memory caching for API responses

Blockchain Solidity + Hardhat + Ethers.js ├── Smart Contracts: Deployed on Etherlink ├── Development: Hardhat for testing and deployment ├── Integration: Ethers.js for contract interaction └── Testing: Comprehensive test suite with Chai

Development Challenges & Solutions Challenge 1: Cross-Chain State Management Problem: Maintaining consistent state across multiple chains Solution: Implemented global state management with real-time synchronization Challenge 2: API Rate Limiting Problem: 1inch API rate limits affecting user experience Solution: Implemented comprehensive fallback system with mock data Challenge 3: Real-Time Updates Problem: Keeping UI in sync with blockchain state Solution: WebSocket connections with React Query for caching