Senior Web3 Blockchain Developer · 8 Showcase DApps · 100,000+ On-Chain Transactions · 2,000+ Clients
高性能 Web3 AI 量化交易 DApp，支持多链和自动化奖励
安全高效的 USDT 智能理财平台，年化高达 18.5%
现代永续期货交易界面，支持实时图表和多倍杠杆
新一代混合交易所，结合 CEX 效率与 DEX 透明度
去中心化现实世界资产代币化平台，专注于可再生能源项目
自托管加密支付基础设施，支持波场 TRON、EVM 链和 SUI
用行为价值取代资本门槛，与 AI 共存的去中心化节点网络协议
去中心化预测市场平台
0xx402 is my Web3 developer portfolio showcasing my representative blockchain projects.
Hi, I'm Neil Yan — a Senior Web3 & Blockchain Developer with a proven track record of building production-grade decentralized applications. Looking to hire a Web3 developer? I offer smart contract development, DeFi protocol development, and full-stack DApp development services.
Since 2018, I've served 2,000+ clients worldwide and processed 100,000+ on-chain transactions. Below are 8 representative DApp projects I've built, spanning AI trading systems, DeFi wealth management platforms, perpetual trading engines, hybrid exchanges, RWA tokenization, crypto payment gateways, decentralized prediction markets, and Blackhole Protocol.
My philosophy: Turn your Web3 ideas into reliable, secure products with clean, audited code.
| Area | Expertise |
|---|---|
| Smart Contracts | Solidity, Vyper, Hardhat, Foundry, OpenZeppelin — audit-grade security |
| Frontend | React, Next.js, Vue, TypeScript, Tailwind CSS — high-performance Web3 UI |
| Web3 Integration | Ethereum, Polygon, BNB Chain, Solana, Avalanche, Arbitrum, Optimism & 15+ more |
| Backend | Node.js, Java, Python, MySQL, Redis, Supabase — scalable server architecture |
| Wallet Connection | MetaMask, WalletConnect, Coinbase Wallet, Rabby, Reown AppKit |
| AI Integration | Gemini API, OpenAI, Alibaba Cloud Qwen — AI-powered DApps |
| DevOps | Vercel, Railway, Docker, Alibaba Cloud, Tencent Cloud, AWS |
| Service | Description |
|---|---|
| 🌐 Full-Stack DApp Development | From product design & UI/UX to smart contracts and on-chain deployment |
| 📜 Smart Contract Development | Security-first approach, OpenZeppelin standards, fully tested & audited |
| 💰 DeFi Protocol Development | Lending, AMM, yield aggregators, staking — multi-chain ready |
| 🎨 NFT Platform Development | Minting, marketplace, blind boxes, whitelist, royalty mechanisms |
| 📊 Data Dashboard | On-chain data visualization, TVL/volume analytics, admin panels |
| 🔧 Technical Consulting | Web3 architecture, tech stack selection, code review, gas optimization |
| 🚀 Project Deployment | Deploy on Vercel, Railway, Docker, AWS, Alibaba Cloud, Tencent Cloud |
Development Achievements
| Metric | Data |
|---|---|
| Web3 Products Released | 8 |
| Supported Chains | 15+ (Full EVM Support) |
| Smart Contract Transactions | 100,000+ |
| Clients Served | 2,000+ |
Client Testimonials
"Neil helped me build a DeFi lending protocol. Clean contract code, passed audit smoothly. Fast responses, smooth communication, highly recommended!" — DeFi Project Lead
"Our team was building an NFT marketplace. Neil handled smart contracts and frontend — launched in under a month. Solid tech skills, reliable delivery." — NFT Startup Team
"Needed a multi-chain Web3 DApp, found Neil. He's very familiar with EVM chains — Polygon, Arbitrum, Base all launched smoothly." — Web3 Product Manager
Tech Stack
| Category | Tech |
|---|---|
| Blockchain | Ethereum, Polygon, BNB Chain, Solana, Avalanche, Arbitrum, Optimism |
| Smart Contract | Solidity, Hardhat, Foundry, OpenZeppelin |
| Frontend | React, Next.js, Vue, TypeScript, Tailwind CSS |
| Web3 | Ethers.js, viem, wagmi, Reown AppKit |
| Backend | Node.js, Java, Python, Express, Spring Boot |
| Database | MySQL, PostgreSQL, Redis, Supabase |
| AI | Google Gemini API, OpenAI, Alibaba Cloud Qwen |
| Deployment | Vercel, Railway, Docker, Aliyun, Tencent Cloud, AWS |
Have a Web3 project in mind? Let's talk:
Telegram is the fastest way to reach me. Please include a brief description of your project 👋
Last updated: April 2026
