Very popular jobPosted 14 days ago · Closes in 17 days

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

Full Stack Developer
$5000 Remote Popular
Private client
United States · Individual
Contact via Twine

We’re looking for an experienced Senior Full-Stack Developer to improve an existing e-commerce application and add crypto wallet and payment functionality. This is not a greenfield project: the application is already functional, and we need someone who can understand the current codebase, modernize it without unnecessary rewrites, and make pragmatic technical decisions independently.

You will improve the architecture, APIs, validation, performance, error handling, and payment flow. The work includes integrating browser wallets such as MetaMask and Rabby, adding EVM testnet crypto payments, verifying blockchain transactions on the backend, connecting payments to existing orders, and handling pending, failed, cancelled, and successful transactions. 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 wallet integrations, transaction security, and testing end-to-end payment flows is required. Initial development will use testnet only, with delivery expected after one month.

Budget range:
Up to $5000

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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