Senior Smart Contract Engineer (Security Focus)

About the role

ether.fi, a DeFi platform offering non-custodial products (Stake, Liquid, Cash and Lend), is hiring a Senior Smart Contract Engineer with a security focus. You will design and build contracts that protect billions of dollars in user assets, review the changes that matter most, and help shape how the company deploys, operates and monitors its on-chain systems. You will work closely with engineering leadership.

Key responsibilities

• Design, build and own smart contracts and backend across Stake, Liquid and Cash, with limited blast radius, clear access control and safe upgrade paths.
• Review and audit contract changes before mainnet, and act as the go-to reviewer for the team.
• Work with external auditors from scoping through fix verification.
• Help design transaction signing, including multisig structure, signer workflows, calldata and transaction hash verification, and timelock usage.
• Improve on-chain operations such as upgrades, parameter changes, role grants, fund movements and bridges so each follows a clear, reviewable path.
• Build monitoring and alerting for contract state, privileged actions, oracle behavior and anomalous flows, and contribute to incident response playbooks.
• Propose and drive security practices and policies, and help other engineers write safer contracts.

Required profile

• Has led a smart contract team and dApp operations.
• Built sophisticated DeFi applications from scratch and operated them.
• Strong fundamentals in software engineering and a deep interest in secure smart contract code, edge cases and failure modes.
• Sound judgment on trade-offs between safety and shipping speed, and the ability to explain them clearly.
• Uses AI tools heavily and reliably to review code, investigate issues and automate operational work.

Required skills

• Solidity
• Upgrade patterns, access control, oracle and cross-chain messaging risks, and common DeFi attack vectors
• Hands-on experience with multisigs, timelocks and governance flows in production

What we offer

• Salary of $120K-$230K, with performance-based incentives and a token allocation grant.
• Health, dental and vision insurance.
• 4 weeks of work from anywhere.
• Global team with opportunities for travel and working out of three offices worldwide.