Blockchain Engineer

Quantum Technologies LLC; Jersey City (NJ); On-site; USD 75,000 - 107,000; Full time

Job summary

Quantum Technologies LLC in Jersey City, NJ, seeks a Blockchain Engineer to design and build Web3 platform services for tokenization, connectivity, and asset management. The role includes integrating with Ethereum/EVM, Hyperledger Besu, Canton/Daml, and Layer 2 solutions in enterprise systems.

The contract runs for 8 months with potential extension and requires familiarities with JSON-RPC, WebSocket, and smart contract interactions across on-prem and cloud environments.

Responsibilities

• Design and build reusable Web3 platform services for tokenization, blockchain connectivity, wallet integration, and token lifecycle management.
• Develop backend services that interact with blockchain nodes, smart contracts, custody platforms, signing systems, and off‑chain enterprise applications.
• Build abstraction layers supporting Ethereum/EVM, Hyperledger Besu, Canton/Daml, Layer 2 solutions, permissioned networks, and consortium blockchains.
• Implement blockchain integrations using JSON-RPC, WebSocket subscriptions, contract queries, transaction submission, status tracking, and event processing.
• Engineer and maintain connectivity solutions for Besu, Ethereum-compatible networks, and permissioned EVM ecosystems.
• Support Canton/Daml workflows including connectivity, authorization, lifecycle management, and workflow integration.
• Manage Daml application packages including deployment, versioning, validation, installation, and production enablement.
• Design, develop, integrate, and review smart contracts for tokenized assets and programmable workflows.
• Build interaction frameworks for ABI encoding/decoding, transaction simulation, calldata generation, and contract state management.
• Establish engineering standards for smart contract development, testing, deployment, governance, rollback planning, and production releases.
• Implement smart contract security best practices including threat modeling, static analysis, fuzz testing, and secure deployment pipelines.
• Integrate wallet, custody, signing, and authorization platforms to support asset management and transaction workflows.
• Design transaction orchestration services covering validation, routing, signing, submission, tracking, exception handling, and audit logging.
• Develop address management, transaction limits, allowlists, approvals, signing policies, and governance mechanisms.
• Collaborate with platform, infrastructure, security, and operations teams to deliver scalable Web3 solutions for enterprise digital assets.

Job description

US Citizen, Green Card, H-1B, OPT-EAD, CPT, Other

Job Title:Blockchain Engineer

Location: Jersey City, NJ

Duration: 8 Months + Extension

Bill Rate: $66/hour (C2C)

Job Type: W-2, 1099, C2C

Client: To Be Discussed Later

Work Authorization: US Citizen, Green Card, OPT-EAD, CPT, H-1B, H4-EAD, Other

Job Summary:

Key Responsibilities:

• Design and build reusable Web3 platform services for tokenization, blockchain connectivity, wallet integration, transaction processing, event ingestion, indexing, and token lifecycle management.
• Develop backend services that interact with blockchain nodes, smart contracts, custody platforms, signing systems, and off-chain enterprise applications.
• Build common blockchain abstraction layers supporting Ethereum/EVM, Hyperledger Besu, Canton/Daml, Layer 2 solutions, permissioned networks, and consortium blockchains.
• Implement blockchain integrations using JSON-RPC, WebSocket subscriptions, smart contract queries, transaction submission, status tracking, and event log processing.
• Engineer and maintain connectivity solutions for Hyperledger Besu, Ethereum-compatible networks, and permissioned EVM-based blockchain ecosystems.
• Support Canton/Daml-based blockchain workflows including participant connectivity, transaction authorization, application lifecycle management, and workflow integration.
• Manage Daml application packages, including deployment, versioning, validation, installation, and production enablement processes.
• Design, develop, integrate, and review smart contracts for tokenized assets, programmable workflows, and digital asset platforms.
• Build smart contract interaction frameworks for ABI encoding/decoding, transaction simulation, calldata generation, event processing, and contract state management.
• Establish engineering standards for smart contract development, testing, deployment, version control, governance, rollback planning, and production releases.
• Implement smart contract security best practices including threat modeling, static code analysis, fuzz testing, invariant testing, and secure deployment pipelines.
• Integrate institutional wallet, custody, signing, and authorization platforms to support blockchain-based asset management and transaction workflows.
• Design transaction orchestration services covering validation, approval routing, policy enforcement, signing, submission, confirmation tracking, exception handling, and audit logging.
• Develop and maintain address management, transaction limit controls, allowlists, approval workflows, signing policies, and operational governance mechanisms.
• Collaborate with platform, infrastructure, security, and operations teams to design scalable, secure, and production-ready Web3 solutions for enterprise digital asset and tokenization platforms.

We are an equal opportunity employer. All aspects of employment including the decision to hire, promote, discipline, or discharge, will be based on merit, competence, performance, and business needs. We do not discriminate on the basis of race, color, religion, marital status, age, national origin, ancestry, physical or mental disability, medical condition, pregnancy, genetic information, gender, sexual orientation, gender identity or expression, national origin, citizenship/ immigration status, veteran status, or any other status protected under federal, state, or local law.