Blockchain Engineer
ether.fi · Cayman +3 · 11d ago
About us
ether.fi is a fast-growing crypto-native financial platform on a mission to put users in control of their wealth, making it easy to save, earn, and spend crypto. As a leading decentralized finance (DeFi) bank, ether.fi offers a fully integrated, non-custodial suite of products (Stake, Liquid, and Cash) that bridge crypto utility with real-world convenience.
Nonce is the team behind ether.fi's DeFi yield vaults, the products that take user deposits and put them to work across DeFi. A depositor gets a single position and a yield-bearing token. Behind it sits a mandate, a set of whitelisted protocols and strategies, live NAV accounting, and a redemption path that has to stay honest whether the market is calm or not. The whole job is deploying into lending markets, LSTs and LRTs, basis and funding trades, stablecoin strategies, and whatever comes next, safely, with the risk understood before the capital moves.
It's a small team with a lot of autonomy. Every vault, every rebalance, and every new protocol integration goes through this team.
Learn more at ether.fi.
Position overview
We're hiring a smart contract / backend engineer to help build and operate ether.fi's DeFi yield vaults. You'll write the contracts that allocate user capital, build the tooling/systems that runs 365/24/7 to safely monitor and manage the capital.
The immediate focus is the next generation of Nonce's vault product to power one of the largest DeFi yield vaults products in the industry. Getting that right, and keeping it secure, is the main thing this role is here to do.
This is a build-and-operate role. You'll ship Solidity and backend services, and you'll also share the day-to-day of running live vaults: discussing new yield opportunities, reviewing transactions, signing them, and deciding whether a new protocol is safe to allocate into. The team is small, so the people who write the vaults are the people who run them.
This role is onsite 4 days per week at one of our global offices: NYC, Denver, or the Cayman Islands.
What you'll work on
Vaults
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, 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: 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 in the first place
Backend services
Build and maintain the critical systems that run 365/24/7 without failure: the solver powering redemption flows, including the liquidity buffer, report NAV changes, security concerns and unwind logic behind them
Build and maintain the NAV service, pricing every position a vault holds, and the accuracy guarantees behind the share price
Automate on-chain operations so allocation, harvesting, and rebalancing run reliably without a human in the loop
Risk and protocol operations
Own the new-protocol review pipeline: given a new protocol, read the docs and contracts, assess the risk, and decide whether and on what terms we allocate
Review and sign vault rebalancing transactions as a multisig signer
Build monitoring and automation that catches a broken oracle, a depeg, a stuck withdrawal, or a bad allocation before users do
Participate as a security guardian across ether.fi's web3 stack and operations
You might be a fit if you
Write strong production Solidity: clean, secure, and designed around edge cases and failure modes
Are equally strong on the backend: services, automation, and tooling that hold up when they're running against real money
Know DeFi deeply enough to read a protocol's docs and contracts, understand where the yield actually comes from, and form your own view on where it breaks
Have 4+ years of industry engineering experience
Have shipped a real yield vault (ERC-4626, BoringVault-style, or your own architecture) and operated it after launch
Thrive in fast-moving environments where the best idea wins
Bonus
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 with the strategies themselves: lending markets, LSTs and LRTs, basis and funding trades, stablecoin yield
Audit or security review background
You've hacked on this for fun: your own contracts, protocol audits, MEV bots, or just a lot of hours across DeFi protocols