Blockchain Engineer

As a Blockchain Engineer at ether.fi, you'll help build and operate DeFi yield vaults that allocate user capital across lending markets, liquid staking tokens, basis trades, and other yield strategies. You join Nonce, the team behind ether.fi's vault products, in a small, autonomous group where every vault deployment, rebalance, and protocol integration passes through your hands. The immediate focus is the next generation of Nonce's vault product to power one of the largest DeFi yield vault products in the industry.

What you'll do

• Design, write, deploy, and configure yield vault smart contracts alongside the rest of the vault team
• Build vault tooling: putting on trades, rebalancing across strategies, updating vault policies and whitelists, and admin configuration
• Extend the vault architecture as new yield strategies, assets, and chains come online
• Review teammates' contracts and tooling, and get reviewed in turn
• Prove the contracts do what they claim through unit and fuzz tests, invariants, and formal verification where it earns its keep
• Work with external auditors through review cycles and write contracts that are straightforward to audit
• Build and maintain critical backend systems that run continuously without failure: the solver powering redemption flows including the liquidity buffer, NAV change reporting, and unwind logic
• Build and maintain the NAV service, pricing every position a vault holds and guaranteeing share price accuracy
• Automate on-chain operations so allocation, harvesting, and rebalancing run reliably without manual intervention
• Own the new-protocol review pipeline: read docs and contracts, assess risk, and decide whether and on what terms to allocate capital
• Review and sign vault rebalancing transactions as a multisig signer
• Build monitoring and automation that catches broken oracles, depegs, stuck withdrawals, and bad allocations before users do
• Participate as a security guardian across ether.fi's web3 stack and operations

What you bring

• Strong production Solidity experience: clean, secure code designed around edge cases and failure modes
• Equally strong backend engineering: services, automation, and tooling that hold up when running against real money
• Deep DeFi knowledge: you can read a protocol's docs and contracts, understand where the yield comes from, and form your own view on where it breaks
• 4+ years of industry engineering experience
• Shipped a real yield vault (ERC-4626, BoringVault-style, or your own architecture) and operated it after launch

Nice to have

• Experience at a vault platform, asset curator, or yield product with real TVL, either building the vaults or curating what goes into them
• Hands-on experience with yield strategies: lending markets, LSTs and LRTs, basis and funding trades, stablecoin yield
• Audit or security review background
• Personal projects: your own contracts, protocol audits, MEV bots, or extensive hours across DeFi protocols

What we offer

• Onsite 4 days per week at one of our global offices: NYC, Denver, or the Cayman Islands

About ether.fi

ether.fi is a crypto-native financial platform building a decentralized finance (DeFi) bank with a fully integrated, non-custodial suite of products that bridge crypto utility with real-world convenience. Nonce, the team behind ether.fi's DeFi yield vaults, manages deposits across whitelisted protocols and strategies with live NAV accounting and reliable redemption paths in all market conditions.