Senior Blockchain Engineer – Domain Modeling

Northbay Systems

Contract · Remote · Flexible hours

About the role

Northbay Systems is launching a security hardening initiative for its cloud‑hosted blockchain applications. As a Blockchain Engineer you will lead the fortification of the newly built "Nimbus Ledger" module, ensuring cryptographic robustness and compliance with industry standards.

Key responsibilities

• Conduct threat modeling and vulnerability assessments on the Nimbus Ledger smart‑contract suite using MythX and Slither.
• Design and implement gas‑optimized security patches in Solidity, integrating with existing CI/CD pipelines on GitHub Actions.
• Automate security testing workflows with Hardhat, Truffle, and Docker‑based test nets deployed on AWS.
• Collaborate with cloud ops to enforce IAM policies and KMS encryption for on‑chain key management.
• Produce detailed audit reports and remediation plans for each sprint milestone.

Must-have skills

• 5+ years developing Solidity smart contracts and auditing code.
• Deep understanding of blockchain security patterns, replay attacks, and side‑chain integrations.
• Proficiency with Ethereum tooling (Hardhat, Truffle, Ganache) and cloud environments (AWS, Azure).
• Experience scripting security automation in JavaScript and Python.
• Strong knowledge of cryptographic primitives and REST API design for blockchain gateways.

Nice to have

• Familiarity with zk‑SNARKs or other zero‑knowledge proof frameworks.
• Previous work on DeFi protocol hardening.