Popular jobPosted 13 days ago · Closes in 17 days

Senior Full-Stack Developer — E-commerce + Crypto WalletUrgent

Full Stack Developer
$750–$1,500 Remote Popular
Private client
United States · Individual
Contact via Twine

We need a senior full-stack developer to improve an existing e-commerce application and add crypto wallet and payment functionality. The app is already functional, so the work should focus on understanding and modernising the current codebase without unnecessary rewrites. You will improve the architecture, APIs, validation, performance, error handling, and existing payment architecture.

You will integrate browser wallets such as MetaMask and Rabby, add EVM testnet payments, implement backend blockchain transaction verification, and connect crypto payments to existing orders. The work includes handling pending, failed, cancelled, and successful transactions, then testing and stabilising the complete payment flow. The stack includes React, TypeScript, Node.js, Express, SQLite, REST APIs, Ethereum/EVM, WalletConnect, and libraries such as ethers.js, viem, or wagmi. Strong experience with e-commerce payments, Web3, transaction security, and working independently on existing applications is required. Initial development will use testnet only, with delivery needed within two months.

Budget range:
Small project ($750 – 1,500 USD)

Hiring as
Individual
Hiring stage
I will possibly make a paid hire
Work type
Full-time position (Contract)
Experience level
Mid-level, senior

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