Web3 Engineer

As a Web3 Engineer at Wonnpay FZE, you design, develop, and maintain blockchain and Web3 services supporting the WonnPay platform. You work across multiple blockchain networks including Ethereum, Polygon, Tron/TRC-20, and Solana, building secure, production-ready crypto infrastructure for on and off-ramp flows, deposit and withdrawal systems, and institutional wallet integrations.

What you'll do

• Design, develop, and maintain blockchain and Web3 services supporting the WonnPay platform
• Integrate and maintain blockchain networks such as Ethereum, Polygon, Tron/TRC-20, Solana, and other supported networks
• Build and maintain crypto deposit and withdrawal flows, including address generation, transaction monitoring, confirmations, fee handling, and reconciliation
• Implement on and off-ramp integration and virtual bank account (VIBAN) functionality
• Work with Fireblocks and other blockchain infrastructure providers for wallet and transaction management
• Develop secure APIs and backend services for blockchain-related functionality
• Implement blockchain transaction monitoring, retry mechanisms, failure handling, and reconciliation processes
• Work with stablecoins such as USDT and USDC across multiple networks
• Support integration of additional digital assets and networks as the product expands
• Work closely with Backend, Frontend, Product, QA, Compliance, and Operations teams to deliver production-ready Web3 features
• Investigate and resolve blockchain transaction issues, including stuck, failed, delayed, or incorrectly routed transactions
• Monitor blockchain infrastructure and proactively identify reliability, performance, and security issues
• Implement appropriate security controls around private keys, signing processes, wallet operations, and transaction authorization
• Participate in architecture discussions, technical design, code reviews, testing, and production releases
• Prepare technical documentation for blockchain integrations and operational procedures
• Support incident investigation and root-cause analysis for blockchain-related production issues

What you bring

• 5+ years of professional software engineering experience with strong hands-on experience in blockchain/Web3
• Strong understanding of blockchain fundamentals: wallets, addresses, transactions, gas/fees, confirmations, and network mechanics
• Hands-on experience with EVM-compatible networks and blockchain transaction processing
• Hands-on experience integrating crypto on-ramp and off-ramp solutions
• Experience with virtual bank account / Virtual IBAN setup and integration
• Experience integrating payment, banking, fiat-to-crypto, and crypto-to-fiat providers
• Experience building or integrating deposit, withdrawal, settlement, and reconciliation flows
• Experience with wallet infrastructure, custody platforms, or blockchain payment providers
• Strong understanding of transaction signing, wallet security, private-key/MPC concepts, and blockchain security
• Experience with blockchain APIs, RPC providers, explorers, webhooks, and transaction monitoring
• Strong backend development experience using Node.js/TypeScript, Python, Go, or similar technologies
• Experience designing and consuming REST APIs and event-driven services
• Experience with databases such as PostgreSQL/MySQL and distributed systems
• Strong troubleshooting skills for failed, delayed, stuck, or incorrectly routed blockchain transactions
• Experience with Fireblocks or similar MPC/custody platforms
• Experience with Solana/SPL tokens
• Experience integrating crypto payment providers or exchanges
• Experience with Chainalysis or other blockchain compliance/monitoring platforms
• Experience with blockchain indexing and event processing
• Experience with smart contract development using Solidity
• Experience with AWS and cloud-native infrastructure
• Experience working in fintech, payments, crypto, or regulated financial services
• Experience building high-volume transaction processing systems

Nice to have

• Strong experience with TRON/TRC-20
• Experience working in fintech, payments, crypto, exchanges, wallets, or regulated financial services