Smart Contract Engineer (Solidity, EVM)

Saifuro LLC; United States; Remote; USD 170,000 - 220,000; Full time

Benefits offered by this job

Equity 0.30%

Health insurance

Vacation 25 days + holidays

Parental leave 14 weeks

Laptop provided

Learning budget $1500

Job summary

Saifuro LLC is hiring a Solidity developer to own on-chain escrow and verification systems. You will build and maintain contracts that hold funds securely, verify signatures on-chain, and prepare for audits and releases with deployment scripts and recovery playbooks.

The role includes expanding to additional EVM chains and milestones, with a strong emphasis on security, reliability, and scalable architecture at pace.

Qualifications

• Shipped Solidity to mainnet.
• Experience with on-chain contracts and verifiable signatures.
• Strong understanding of EVM and related tools.

Responsibilities

• Own the escrow contract system on Base: design, code and tests.
• Own the verifier path onchain: signature checks, audience and expiry.
• Coordinate audits and releases with external auditors and deployment scripts.

Skills

Solidity

Smart contract

On-chain verification

Mainnet deployment

Job description

Saifuro checks payments that AI agents try to make. An agent asks to spend, we compare the request with a mandate a human approved earlier, and the answer comes back signed so the receiving side can verify it. There's escrow on Base and Solana for trades between agents, and settlement is in USDC, onchain. We never hold customer funds. The docs are public at docs.saifuro.com, and the people who use them are developers building agents and the teams selling APIs to those agents.

The escrow is the one place where our code holds other people's money. Funds go in, sit until a signed verdict says the deal is done, and come out to the seller or back to the buyer, with no path in which Saifuro can move them. Your job is to own the EVM side: the escrow, the verifier that checks our signatures onchain, the audits and the deployments. Call it Solidity developer, smart contract developer or blockchain developer if you prefer. It's Solidity first.

What you'd be doing

• The escrow. One contract system on Base: funds held until a signed verdict releases them, refunds that work without us, and no path in which Saifuro can move a counterparty's money. Design, code and tests are yours.
• The verifier. The contracts check our signature, the audience and the expiry before anything moves. You own that path onchain. The CTO runs the signing side and reviews your code.
• Audits and releases. An external audit before every mainnet release. You scope it, answer the findings and ship, with deployment scripts, a pause switch and a recovery runbook alongside.
• What comes next, at your pace. Milestone and multi-party escrow next year, and the same contracts on more EVM chains. None of it is a day-one requirement.

What we need from you

• You’ve shipped Solidity to mainnet.
• You live in one of the countries we can hire in.

Beyond these requirements, we’ll support you in learning whatever else the role demands. If your experience is relevant but your title differs, we would still like to hear from you. Work outside a job counts too: open source, hackathons and your own projects.

It helps, but isn’t required, if you know storage layout, reentrancy and signature verification at the EVM level, if you’ve written Rust or Anchor programs on Solana, if you’ve worked with account abstraction (ERC-4337) or session keys for agents, if you know Circle’s USDC contracts and CCTP, if you’ve found bugs for a bounty or did security research, or if your work is open source.

Pay and benefits

• Salary $170,000 to $220,000. That’s the US range. Outside the US we pay in USD, or in USDC if you’d rather, and set the offer against the top of the local market.
• Equity: 0.30% of Saifuro, vesting.
• Health: 100% of medical, dental and vision premiums for US employees, 75% for dependents.
• Outside the US, the local plan through our employer of record, or $300 a month toward private cover.
• 25 days of paid vacation plus your public holidays, and we close between Christmas and New Year.
• 14 weeks of paid parental leave, for any parent.
• A laptop and $1,000 toward your workspace.
• $1,500 a year for learning, conferences included. That’s on top of the events you’ll attend for work: six to eight a year, planned a quarter ahead, on the company.

Hours are flexible. The one thing we ask is to be online from 14:00 to 17:00 UTC, when the team overlaps for calls and quick questions. That’s a window, not the working day. The rest of your hours are yours to arrange. A mainnet incident doesn’t keep office hours. If that window is the middle of your night, say so and we’ll work something out.

You can combine this with a job at another company, as long as the two don’t conflict and nothing you’d write there touches our contracts or competes with them.