Blockchain Developer — Reuben Cooley Inc.

The Bitcoin Street Journal; Jersey City, Northern (NJ, KY); On-site; USD 120,000 - 190,000; Full time

Job summary

The Bitcoin Street Journal is seeking an experienced backend engineer to design and build Web3-enabled services for a Digital Asset Platform. You will work on blockchain integrations, smart contracts, and on-chain event handling.

This role emphasizes scalable Java/Spring or Node.js backend development, security audits, and collaboration with cross-functional teams to deliver reliable, performant systems across the stack.

Qualifications

• Bachelor’s degree in CS or engineering; MS preferred.
• 8+ years software engineering with strong backend focus.
• 2–4 years Web3/blockchain app development, including smart contracts.
• 3–5 years backend with Java/Spring or Node.js.

Responsibilities

• Design, develop, and deploy Web3 components and integrations for a Digital Asset Platform, including smart contracts, on-chain event listeners, wallet integrations, and blockchain protocol connectors.
• Build and maintain backend services that interface with public and permissioned blockchain networks (e.g., Ethereum, Hyperledger Besu, Corda, or equivalent).
• Develop, test, and audit smart contracts written in Solidity or equivalent languages, ensuring security, correctness, and gas efficiency.
• Integrate Web3 libraries and SDKs (e.g., Web3J, Web3JS, Ethers.js, Viem) into enterprise Java and/or Node.js backend services.
• Implement asynchronous, event-driven architectures to handle on-chain events, transaction lifecycle management, and blockchain state synchronization.

Skills

Backend development

Java/Spring

Node.js

Web3 blockchain

Smart contracts

Education

Bachelor's degree in CS/Engineering

MS preferred

Tools

Web3J

Web3JS

Ethers.js

Viem

Blockchain SDKs

Job description

• Location: NJ Jersey City US
• Sector: Blockchain
• Source: web3.career

Key Responsibilities

• Design, develop, and deploy Web3 components and integrations for a Digital Asset Platform, including smart contracts, on-chain event listeners, wallet integrations, and blockchain protocol connectors.
• Build and maintain backend services that interface with public and permissioned blockchain networks (e.g., Ethereum, Hyperledger Besu, Corda, or equivalent).
• Develop, test, and audit smart contracts written in Solidity or equivalent languages, ensuring security, correctness, and gas efficiency.
• Integrate Web3 libraries and SDKs (e.g., Web3J, Web3JS, Ethers.js, Viem) into enterprise Java and/or Node.js backend services.
• Implement asynchronous, event-driven architectures to handle on-chain events, transaction lifecycle management, and blockchain state synchronization.

Qualifications / Experience

• Bachelor’s degree in Computer Science, Engineering, or a related discipline; MS is a plus.
• 8+ years of overall software engineering experience, with a strong backend development foundation.
• 2 to 4 years of hands‑on experience in Web3 and blockchain application development, including smart contract development and blockchain protocol integration.
• 3 to 5 years of experience with backend development using Java/Spring, Node.js, or equivalent enterprise frameworks.