Senior Web3 Blockchain Engineer - Smart Contracts & Backend

Tech Mirrors; New York (NY); On-site; USD 120,000 - 180,000; Full time

Job summary

Tech Mirrors is seeking a Blockchain Developer to design, implement, and audit Web3 components for enterprise-grade applications. You will work across smart contracts, on-chain data, and backend services interfacing with Ethereum and permissioned networks.

The role requires 8+ years in software engineering with strong backend skills and hands-on Web3 experience. Expect a collaborative, cross-functional team working in an Agile environment on distributed systems.

Qualifications

• Bachelor’s degree in Computer Science/Engineering (MS preferred).
• 8+ years of software engineering experience with strong backend focus.
• 2–4 years hands-on Web3 and blockchain development including smart contracts.
• 3–5 years backend development with Java/Spring or Node.js.
• Proficiency in Solidity and security best practices.
• Hands-on Web3 libraries: Web3J, Web3JS, Ethers.js, Viem.
• Solid understanding of blockchain fundamentals and token standards.
• Experience with permissioned networks like Hyperledger Besu, Fabric, or Corda.

Responsibilities

• Design, develop, and deploy Web3 components for enterprise platforms, including smart contracts and wallet integrations.
• Build and maintain backend services interfacing with blockchain networks (Ethereum, Hyperledger, Corda).
• Develop, test, and audit smart contracts ensuring security and gas efficiency.
• Integrate Web3 libraries into enterprise Java and Node.js backends.
• Implement asynchronous, event-driven architectures for on-chain events and state synchronization.
• Collaborate with architects to design scalable, secure Web3 infrastructure.
• Participate in code reviews and maintain engineering standards.
• Support asset custody, tokenization frameworks, and DeFi/TradFi bridging components.
• Document technical specs, integration guides, and architecture notes.
• Stay current with Web3 ecosystem and protocol upgrades; work in Agile/Scrum within distributed teams.
• Identify and resolve cross-stack issues to ensure timely delivery.

Skills

Web3 development

Backend engineering

Security best practices

Agile collaboration

Delivery focus

Code quality

Tooling proficiency

Education

Bachelor’s degree in Computer Science or Engineering

MS degree desired

Tools

Web3J

Web3JS

Ethers.js

Viem

Java/Spring

Node.js

Hardhat

Foundry

Truffle

Docker

Kubernetes

Kafka

RabbitMQ

Job description

Tech Mirrors is seeking a Blockchain Developer to design, implement, and audit Web3 components for enterprise-grade applications. You will work across smart contracts, on-chain data, and backend services interfacing with Ethereum and permissioned networks.

The role requires 8+ years in software engineering with strong backend skills and hands-on Web3 experience. Expect a collaborative, cross-functional team working in an Agile environment on distributed systems.