Blockchain Engineer

Workload: full-time
Start: 1st of November
Duration: long-term (2-year contract)
Location: any, but preferably Ukraine or Europe
English: B2

Required expertise: at least 2 years of experience with Solidity and Javascript/Typescrypt!

We are building the next generation of onchain index products, making diversified crypto exposure simpler, more transparent, and accessible through a single token.
We are looking for a Smart Contracts Developer to join our team and help design, develop, test, and maintain the smart contracts powering the Indexfy ecosystem.

What you'll do

• Design and develop secure, gas-efficient Solidity smart contracts.
• Build and improve the infrastructure behind Indexfy's onchain index products.
• Develop vaults, token contracts, fee mechanisms, and other DeFi protocols.
• Write comprehensive unit and integration tests.
• Review and improve existing smart contracts with a strong focus on security.
• Participate in smart contract architecture and protocol design decisions.
• Integrate contracts with protocols such as Uniswap, Aave, Chainlink, and other DeFi infrastructure where relevant.
• Work closely with backend and frontend developers to integrate onchain functionality.
• Assist with contract deployments, upgrades, monitoring, and maintenance across EVM-compatible networks.
• Contribute to security reviews and prepare contracts for external audits.

Requirements

• Strong experience with Solidity and EVM-based blockchains.
• Solid understanding of ERC-20, ERC-4626 and DeFi protocols.
• Experience with Hardhat, Foundry or similar development frameworks.
• Strong understanding of smart contract security and common Solidity vulnerabilities.
• Experience writing automated tests for smart contracts.
• Good understanding of blockchain architecture, transactions, gas optimization, and contract interactions.
• Familiarity with OpenZeppelin contracts and libraries.
• Ability to write clean, maintainable, and well-documented code.

Nice to have

• Experience with Base / Ethereum.
• Experience with Uniswap V3/V4, Aave, Chainlink or other DeFi protocols.
• Experience building vaults, index products, AMMs or financial protocols.
• Experience with cross-chain protocols such as Chainlink CCIP or LayerZero.
• Previous experience preparing smart contracts for security audits.
• Contributions to open-source blockchain projects.