Senior Smart Contract Developer – Pet360 (Blockchain, Solidity, EVM)

About the Project

We are building Pet360 — the first blockchain-based pet ecosystem in Brazil. 160 million pets, $60 billion market, zero blockchain infrastructure today.

Our Web2 platform is 75% complete. We are now building the Web3 layer from scratch — pet NFT passports, vaccine certificates, smart contract adoptions, and on-chain pet insurance.

We are looking for a Senior Smart Contract Developer to join our team.

What You Will Do

• Write and deploy Solidity smart contracts (ERC-721 for pet passports, ERC-1155 for vaccine certificates)
• Implement upgradeable contract patterns (UUPS) for future flexibility
• Write comprehensive tests using Foundry or Hardhat
• Optimize gas usage and ensure security best practices
• Design the on-chain architecture for pet identity, vaccine verification, and insurance claims
• Work alongside our backend and frontend teams

What We Are Looking For

• 3+ years of software development experience
• 1+ year of Solidity and EVM development
• Strong understanding of ERC-721 and ERC-1155 standards
• Experience with Foundry or Hardhat
• Understanding of smart contract security and gas optimization
• Experience with upgradeable contract patterns (UUPS or Transparent proxies)
• Professional English proficiency

Nice to have:

• Experience with multi-chain deployments (Polygon, Ethereum, BSC)
• Experience with smart contract auditing
• Experience with IPFS and decentralized storage
• Experience with AI-assisted development (Cursor, Claude Code)

What We Offer

• Fully remote — work from anywhere
• Contract with long-term growth potential
• 30+ hours per week
• $70-120 per hour (negotiable)
• Founding team token allocation
• Payment in crypto (USDC/USDT) or fiat (Wise/PayPal)